Intestinal obstruction

Intestinal obstruction occurs when intestinal contents cannot pass through the GI tract. The obstruction may occur in the small intestine or colon and can be partial or complete. Intestinal obstruction requires prompt treatment.

TYPES OF INTESTINAL OBSTRUCTION

The causes of intestinal obstruction can be classified as mechanical or non-mechanical.

Mechanical

Mechanical obstruction is a detectable occlusion of the intestinal lumen. Most intestinal obstructions occur in the small intestine. Surgical adhesion is the most common cause of small bowel obstructions and can occur within days of surgery or several years later. Hernias and tumours are the next most common causes, followed by small bowel strictures, which may occur as a consequence of inflammatory disease. Carcinoma is the most common cause of large bowel obstruction, followed by volvulus, diverticular disease and faecal impaction (see Fig 42-6).

Figure 42-6 Bowel obstructions. A, Adhesions. B, Strangulated inguinal hernia. C, Ileocaecal intussusception. D, Intussusception from polyps. E, Mesenteric occlusion. F, Neoplasm. G, Volvulus of the sigmoid colon.

Non-mechanical

A non-mechanical obstruction may result from a neuromuscular or vascular disorder. Paralytic (adynamic) ileus (lack of intestinal peristalsis and the presence of no bowel sounds) is the most common form of non-mechanical obstruction. It occurs to some degree after any abdominal surgery. It can be difficult to know whether postoperative obstruction is due to paralytic ileus or adhesions, although bowel sounds usually return before postoperative adhesions develop. Other causes include peritonitis, inflammatory responses (e.g. acute pancreatitis, acute appendicitis), electrolyte abnormalities (especially hypokalaemia) and thoracic or lumbar spinal fractures.

Pseudo-obstruction is an apparent mechanical obstruction of the intestine without demonstration of obstruction by radiological methods. Collagen vascular diseases and neurological and endocrine disorders may cause pseudo-obstruction, but many times the cause is unknown.

Vascular obstructions are rare and are due to an interference with the blood supply to a portion of the intestines. The most common causes are emboli and atherosclerosis of the mesenteric arteries. The coeliac, inferior and superior mesenteric arteries supply blood to the bowel. Emboli may originate from thrombi in patients with chronic atrial fibrillation, diseased heart valves and prosthetic valves. Venous thrombosis may be seen in low-blood-flow states, such as heart failure and shock.

AETIOLOGY AND PATHOPHYSIOLOGY

About 6–8 L of fluid enters the small bowel daily. Most of the fluid is absorbed before it reaches the colon. Approximately 75% of intestinal gas is swallowed air. Normally, gastric HCl secretion and rapid movement of chyme through the small intestine inhibit bacterial growth in the small intestine, but bacteria flourish when the small bowel is obstructed. Fluid, gas and intestinal contents accumulate proximal to the obstruction. The distal bowel collapses. The distension reduces the absorption of fluids and stimulates intestinal secretions. Bacteria flourish proximal to the obstruction and stimulate additional secretion of fluids into the bowel. The proximal bowel becomes increasingly distended and intraluminal bowel pressure rises. The increased pressure leads to an increase in capillary permeability and extravasation of fluids and electrolytes into the peritoneal cavity. The retention of fluid in the intestine and peritoneal cavity can lead to a severe reduction in circulating blood volume and result in hypotension and hypovolaemic shock. If blood flow is inadequate, bowel tissue becomes ischaemic, then necrotic and the bowel may rupture. The most dangerous obstruction is when the bowel becomes strangulated and the blood supply is cut off. If not corrected quickly, the bowel will become necrotic and rupture, leading to massive infection and death.

When the bowel is obstructed, electrolyte-rich fluids cannot be absorbed from the bowel and are subsequently lost into the peritoneal cavity. The location of the obstruction determines the extent of fluid, electrolyte and acid–base imbalances. If the obstruction is high, as in the pylorus, metabolic alkalosis may result from the loss of gastric HCl through vomiting or NG intubation. When the obstruction is located in the small bowel, dehydration occurs rapidly. Dehydration and electrolyte imbalances do not occur early in large bowel obstruction. If the obstruction is below the proximal colon, most GI fluids have been absorbed before reaching the point of the obstruction. Solid faecal material accumulates until symptoms of discomfort appear.

Obstructions may be partial or complete. Some obstructions, especially those due to surgical adhesions, may resolve without surgery. Others, such as strangulated obstructions, require emergency surgery for survival. Simple obstructions of the intestine involve blockage of the lumen in one spot. A closed-loop obstruction occurs when the lumen is blocked in two different spots (e.g. volvulus). This results in an isolated segment of bowel and obstruction proximal to that segment. Strangulation and gangrene are likely to develop if treatment is not immediate.

CLINICAL MANIFESTATIONS

The clinical manifestations of intestinal obstruction vary, depending on the location of the obstruction, and include nausea, vomiting, abdominal pain, distension, inability to pass flatus and obstipation (severe constipation caused by bowel obstruction; see Table 42-13). Patients with obstructions located high in the small intestine rapidly develop nausea and vomiting, which is sometimes projectile in nature and contains bile. Vomiting from more distal obstructions of the small intestine is more gradual in onset. The vomitus may be orange–brown and foul smelling, like faeces, because of bacterial overgrowth.

TABLE 42-13 Clinical manifestations of small and large intestinal obstructions

Clinical manifestation	Small intestine	Large intestine
Onset	Rapid	Gradual
Vomiting	Frequent and copious	Rare
Pain	Colicky, cramp-like, intermittent	Low-grade, cramping abdominal pain
Bowel movement	Faeces for a short time	Absolute constipation
Abdominal distension	Greatly increased	Increased

Vomiting usually relieves abdominal pain in high intestinal obstructions. Persistent, colicky abdominal pain is seen with lower intestinal obstruction. A characteristic sign of mechanical obstruction is pain that comes and goes in waves. This is due to intestinal peristalsis trying to move bowel contents past the obstructed area. In contrast, paralytic ileus produces a more constant generalised discomfort. Strangulation causes severe, constant pain that is rapid in onset. Abdominal distension is a common manifestation of intestinal obstructions. It is usually absent or minimally noticeable in high obstructions of the small intestine and greatly increased in lower intestinal obstructions. Abdominal tenderness and rigidity are usually absent unless strangulation or peritonitis has occurred.

Auscultation of bowel sounds reveals high-pitched sounds above the area of obstruction. Bowel sounds may also be absent. The patient often notes borborygmi (audible abdominal sounds produced by hyperactive intestinal motility). The patient’s temperature rarely rises above 37.8°C unless strangulation or peritonitis has occurred.

DIAGNOSTIC STUDIES

A thorough history and physical examination should be performed. Abdominal X-rays are the most useful diagnostic aids. Upright and lateral abdominal X-rays show the presence of gas and fluid in the intestines. The presence of intraperitoneal air indicates perforation. A barium enema is helpful in locating large intestinal obstruction. However, barium is not used if perforation is suspected. If the location is unknown, a lower GI tract study is done before an upper GI series. Sigmoidoscopy or colonoscopy may provide direct visualisation of an obstruction in the colon. CT or MRI scans may also be used in diagnosis.

Laboratory tests are important and provide essential information. FBC and serum electrolyte, amylase and urea determinations should be performed. An elevated WBC may indicate strangulation or perforation; elevated haematocrit values may reflect haemoconcentration. Decreased haemoglobin and haematocrit values may indicate bleeding from a neoplasm or strangulation with necrosis. Serum electrolytes should be monitored frequently to provide essential information about the patient’s fluid and electrolyte balance. Serum sodium, potassium and chloride concentrations are decreased in small bowel obstruction. The serum urea and serum creatinine should be monitored to determine whether fluid resuscitation is adequate to prevent acute renal failure. The stool should be checked for occult blood.

MULTIDISCIPLINARY CARE

Emergency surgery is performed if the bowel is strangulated, but many bowel obstructions resolve with conservative treatment. The initial medical treatment of bowel obstruction due to adhesions includes the patient being NBM, insertion of an NG tube, IV fluid resuscitation with either normal saline or Hartmann’s solution, addition of potassium to IV fluids after renal function is verified and analgesics for pain control. Colon decompression catheters may be passed through partially obstructed areas via a colonoscope or a flatus tube may be inserted to decompress the bowel prior to surgery. If the situation does not improve within 24–48 hours or if the patient’s condition deteriorates, surgery is performed to relieve the obstruction. The goals of treatment are relief of the obstruction, and correction and maintenance of fluid and electrolyte balance. Parenteral nutrition may be necessary in some cases to correct nutritional deficits, improve the patient’s nutritional status before surgery and promote postoperative healing.

Surgery may involve simply resecting the obstructed segment of bowel and anastomosing the remaining healthy bowel back together. Partial or total colectomy, colostomy or ileostomy may be required when extensive obstruction or necrosis is present. Occasionally, obstructions can be removed non-surgically. A colonoscope can be used to dilate strictures or reduce a volvulus.

NURSING MANAGEMENT: INTESTINAL OBSTRUCTION

Polyps of the large intestine

Colonic polyps arise from the mucosal surface of the colon and project into the lumen. They may be sessile (flat, broad-based and attached directly to the intestinal wall) or pedunculated (attached to the intestinal wall by a thin stalk). Polyps tend to be sessile when small and may become pedunculated as they enlarge, especially if they are in the left or descending colon (see Fig 42-7). They may be found anywhere in the large intestine but are most commonly found in the rectosigmoid area. Rectal bleeding and occult blood in the stool are the most common symptoms, but most polyps are asymptomatic.

Figure 42-7 Endoscopic image of a pedunculated polyp in the descending colon.

TYPES OF POLYPS

The most common types of polyps are hyperplastic and adenomatous. Hyperplastic polyps originate from the epithelium and are non-neoplastic growths. They seldom grow larger than 5 mm in size and rarely cause clinical symptoms. Other benign (non-neoplastic) polyps include inflammatory polyps, lipomas and juvenile polyps (see Box 42-11). Adenomatous polyps are characterised by neoplastic changes in the epithelium. They are closely linked to colorectal adenocarcinoma. Structurally, there are three types, with tubular adenomas being the most prevalent. The risk of cancer in the polyp increases with polyp size and villous structure. Villous adenomas have a higher risk of turning cancerous than tubular adenomas. Removing adenomatous polyps has been reported to substantially decrease the occurrence of subsequent colorectal cancer.^38,³⁹

Although there are several polyposis syndromes, they are relatively rare. Of these, familial adenomatous polyposis (FAP) is the most common (see the Health disparities box). This disorder is characterised by multiple polyps, which at times number in the thousands and are located in the large intestine and sometimes in other areas of the GI tract. Patients with a history of untreated FAP have a risk of developing colorectal cancer approaching 100% by the age of 50 years.^38,³⁹ They also develop cancer at an earlier age (i.e. 40 years of age) than patients with non-FAP colorectal cancer. For children of patients with FAP, screening must be initiated at puberty and then conducted annually. There is a 50% risk for these children to develop FAP. Surgery is indicated once there is an endoscopic diagnosis with pathological confirmation that the polyps are adenomas. Surgical options include total colectomy and ileorectal anastomosis or restorative proctocolectomy with pouch formation, usually performed in the teenage years or early adulthood. Lifetime endoscopic follow-up of the rectum or pouch every 12 months is required. The development of severely dysplastic adenomas, endoscopically uncontrollable numbers of adenomas or cancer is an indication for proctectomy. Regular upper GI endoscopy is also required to prevent upper GI malignancy.³⁸

Familial adenomatous polyposis (FAP)

HEALTH DISPARITIES

Incidence

• Very rare (e.g. there are about 2000 affected and at-risk families in Australia)

• Men and women affected equally

Clinical implications

• Accounts for less than 1% of all colorectal cancers.

• Classic FAP is characterised by the presence of colorectal polyps (usually hundreds to thousands).

• Polyps are not present at birth but appear during adolescence and early adulthood.

• Attenuated FAP is characterised by fewer polyps, typically fewer than 100, often only in the proximal colon. Polyps and cancer tend to develop at an older age than classic FAP.

• If untreated, FAP almost always results in the development of colon cancer before the age of 40.

• With classic FAP, other benign and malignant tumours are sometimes found, especially in the duodenum, stomach, bones, skin and other tissues.

• Many deaths related to FAP could be prevented with early and aggressive monitoring and treatment, including frequent colonoscopies and total colectomy.

• Individuals with a family history of FAP could benefit from genetic counselling.

MYH-associated polyposis

• MYH-associated polyposis (MAP) is a recently described condition that results from mutations in the base excision repair gene mutY homologue (MYH). MAP is very similar to attenuated FAP but is inherited as a recessive condition. MYH mutation carriers should be treated and followed up as for FAP patients.

DIAGNOSTIC STUDIES AND MULTIDISCIPLINARY CARE

Colonoscopy is the gold standard for investigating rectal bleeding and diagnosing polyps, as polypectomy (removal of polyps) can be performed at the initial diagnostic procedure.³⁹ However, barium enema, sigmoidoscopy and CT colography (virtual colonoscopy) can also be used to diagnose polyps. As all polyps are considered abnormal, patients whose polyps are identified through barium enema, CT colography or capsule endoscopy will need to have their polyps removed (polypectomy) and then followed up with a colonoscopy. If the polyp is not removable, a biopsy specimen should be taken for tissue examination. Surgery is indicated if carcinoma or severe dysplasia is present or in certain cases of polyposis syndromes. Following polypectomy, the patient should be observed for rectal bleeding, fever, severe abdominal pain and abdominal distension, which may indicate haemorrhage or perforation. Complete polypectomy is a curative procedure; however, if dysplasia is present in the resected bowel, follow-up surveillance colonoscopy is indicated.

Colorectal cancer

Colorectal cancer is the most common cancer reported to the Australian cancer registries and the second leading cause of cancer-related deaths in Australia.⁴⁰ In New Zealand, bowel cancer is the second most frequently diagnosed cancer and the second highest cause of cancer death.⁴¹ Furthermore, New Zealand has the third highest bowel cancer death rate in the OECD for women and the sixth highest for men. Colorectal cancer has an insidious onset and symptoms do not appear until the disease is quite advanced. Therefore, regular screening is necessary to detect precancerous lesions. About half of all colorectal cancers occur in the rectosigmoid area (see Fig 42-8). Fortunately, about 85% of colorectal cancers arise from adenomatous polyps, which can be detected and removed from the rectum and sigmoid colon by sigmoidoscopy or colonoscopy. Since half of all cases are found in areas of the colon that are inaccessible by sigmoidoscopy, colonoscopy is considered the gold standard for the detection and removal of polyps.³⁹

Figure 42-8 Incidence of cancer. Approximately half of all colon cancers occur in the rectosigmoid area. Percentages are listed for males (M) and females (F).

AETIOLOGY AND PATHOPHYSIOLOGY

Colorectal cancer is more common in men than in women. Major risk factors include increasing age, family or personal history of colorectal cancer, colorectal polyps and IBD. About 90% of new colorectal cancer cases are detected in people older than 50. Weaker inheritance factors might contribute to up to 25% of cases. Strong hereditary diseases (e.g. FAP) account for up to 5% of colorectal cancer cases. Hereditary non-polyposis colorectal cancer (HNPCC) syndrome, also called Lynch syndrome, is the most common inherited form of hereditary colorectal cancers (see the Health disparities box).⁴² Certain lifestyle factors are also associated with colorectal cancer. There is some evidence that obesity, smoking, excess alcohol consumption and eating red meat cooked at high temperatures increase the risk. Physical exercise and a diet with large amounts of fruits, vegetables and grains may decrease the risk. Aspirin and non-aspirin NSAIDs have been found to provide a degree of protection from colorectal cancer.^43,⁴⁴ There is also some evidence that the incidence of colorectal cancer is reduced in women who have used hormone replacement therapy; however, the benefits must be balanced against the possible increased risks for breast cancer and stroke.⁴⁴ (See Box 42-12 for a list of risk factors.)

Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch syndrome

HEALTH DISPARITIES

Incidence

• 1 in 500–2000 people

Genetic testing

• DNA testing available

Clinical implications

• Accounts for 1–4% of all colorectal cancers.

• Individual with gene mutation has 70–90% lifetime risk of developing colorectal cancer.

• Average age of diagnosis is in the mid-40s.

• Cancers tend to occur on right side of the colon.

• HNPCC is usually less aggressive and survival rates are longer than colorectal cancer that develops without known risk factors.

• People with HNPCC have an increased risk of cancers of the stomach, small intestine, liver, gall bladder ducts, upper urinary tract, brain and skin.

• Women with HNPCC also have a greatly increased risk of endometrial and ovarian cancer.

• Occasionally people with HNPCC also have colon polyps, which occur at an earlier age than do colon polyps in the general population and are more prone to become malignant.

• Individuals with known gene mutations need to be monitored with colonoscopy every 1–2 years. Upper GI endoscopy and surveillance of the urinary system may also be performed. Examination of the ovaries and uterus by transvaginal ultrasound should be considered for women. Endometrial biopsy is indicated for women with symptoms or abnormal ultrasound findings.

Adenocarcinoma is the most common type of colorectal cancer. Most colorectal cancers begin as adenomatous polyps that arise from the mucosa lining the lumen of the colon and rectum. As it grows, the cancer progresses down from the tip of the polyp through the body and stalk. It becomes invasive and penetrates the muscularis mucosae. Once through the muscularis mucosae, tumour cells gain access to the regional lymph nodes and vascular system and can spread to distant sites. (Carcinomas of the caecum and colon are shown in Fig 42-9.) The most common sites of metastasis are the regional lymph nodes, liver, lungs and peritoneum. Since venous blood leaving the colon and rectum flows through the portal vein and the inferior rectal vein, the liver and lungs are common sites of metastasis. The cancer spreads from the liver to other sites, including the lungs, bones and brain. The cancer can also spread directly into adjacent structures. The growing tumour can obstruct the bowel. Other complications include bleeding, perforation, peritonitis and fistula formation.

Figure 42-9 A, Carcinoma of the caecum. The fungating carcinoma projects into the lumen but has not caused obstruction. B, Carcinoma of the descending colon. This circumferential tumour has heaped up edges and an ulcerated central portion. The arrows identify separate mucosal polyps.

CLINICAL MANIFESTATIONS

Clinical manifestations of colorectal cancer are usually non-specific or do not appear until the disease is advanced. Cancer on the right side of the colon gives rise to clinical manifestations that are different from those on the left side of the colon (see Fig 42-10). Rectal bleeding, the most common symptom of colorectal cancer, is most often seen with left-sided lesions. Other manifestations of left-sided lesions include alternating constipation and diarrhoea, change in stool calibre (narrow, ribbon-like) and a sensation of incomplete evacuation. Obstruction symptoms appear earlier with left-sided lesions because lesions in the descending colon and rectum tend to progressively constrict the lumen and those in the more proximal lumen do not (see Fig 42-10).

Figure 42-10 Signs and symptoms of colorectal cancer by location of primary lesion.

Cancers of the right side of the colon are usually asymptomatic. Vague abdominal discomfort or cramping, colicky abdominal pain may be present. Occult bleeding and iron-deficiency anaemia lead to weakness and fatigue.

DIAGNOSTIC STUDIES

A thorough history with close attention to family history should be obtained (see Box 42-13). Since symptoms of colorectal cancer do not become evident until the disease is advanced, regular screening is advocated to detect and remove polyps before they become cancerous. Routine physical examinations should include a digital rectal examination, since rectal polyps and cancer can be reached with a finger. The Cancer Council Australia and the Australian Cancer Network ³⁸ recommend that people who have no established risk factors should, at a minimum, have a faecal occult blood test (FOBT) or a faecal immunochemical test (FIT) at least every 2 years, starting at the age of 50. All positive tests should be followed up by colonoscopy. In New Zealand a 4-year bowel screening pilot is being conducted from late 2011 to determine whether a bowel screening program should be rolled out nationally.

People with a higher risk of developing colorectal cancer should begin colonoscopic surveillance earlier and have it done more often, with the age of commencement and frequency of surveillance dictated by their risk factors and family history. Risk factors include a personal history of colorectal cancer or adenomatous polyps, a family history of colorectal cancer in a first-degree relative younger than 56 or significant adenomatous polyps in a first-degree relative younger than 40 or in two first-degree relatives of any age, a history of IBD or a history of an hereditary colorectal cancer syndrome (e.g. FAP, HNPCC).

Colonoscopy is appropriate for surveillance of people at higher risk of developing colorectal cancer because of the higher chance of finding polyps or cancer and the greater accuracy of the test. Also, the entire colon can be examined, biopsies can be obtained and polyps can be immediately removed and sent to the laboratory for histological examination. CT colography (virtual colonoscopy) can also detect colorectal lesions. However, as previously noted, biopsies cannot be obtained with this technique. (The differences between conventional and virtual colonoscopies are discussed in Ch 38.)

Since cancerous tumours and large polyps bleed intermittently into the colon, FOBTs are used to detect very small quantities of blood. Two tests are available. Guaiac-based tests require that the patient avoid NSAIDs, vitamin C, certain vegetables eaten raw and red meat for 3 days before the test. Six samples from three consecutive bowel movements are collected and smeared onto a special card. The FIT does not require special dietary restrictions, specifically detects bleeding from the lower intestine and often only needs two or three stool specimens. Neither test detects non-bleeding tumours. In Australia, the FIT is now the gold standard and guaiac-based tests have been phased out,

Ongoing studies are evaluating the sensitivity and specificity of a stool DNA test. DNA markers are shed from premalignant adenomas and cancer cells into the stool and are not degraded. Stools are collected and sent to the laboratory for DNA analysis. Although promising, the DNA test is not yet sensitive enough to replace the other screening methods.⁴⁵

Once colonoscopy and tissue biopsies confirm the diagnosis of colorectal cancer, additional laboratory studies are done, including an FBC to check for anaemia, coagulation studies and liver function tests. Carcinoembryonic antigen (CEA) is a complex glycoprotein produced by 90% of colorectal cancers. It is helpful in monitoring disease recurrence following surgery or chemotherapy. A CT scan or MRI of the abdomen may be helpful in detecting liver metastases, retroperitoneal and pelvic disease, and depth of penetration of the tumour into the bowel wall. However, liver function tests may be normal even when metastasis has occurred.

MULTIDISCIPLINARY CARE

Colorectal cancer prognosis and treatment correlate with pathological staging of the disease. Two staging systems are used in Australia and New Zealand: the TNM staging system (see Box 42-14) of the American Joint Committee on Cancer; and the Duke’s classification system (see Table 42-14). The TNM system is currently the preferred classification system. As with other cancers, prognosis worsens with greater size and depth of tumour, lymph node involvement and metastasis.

BOX 42-14 TNM classification of colorectal cancer

T	Primary tumour
T_x	Primary tumour cannot be assessed because of incomplete information
T_is	Carcinoma in situ; cancer is in the earliest stage and has not grown beyond the mucosa layer
T₁	Tumour has grown beyond mucosa into the submucosa
T₂	Tumour has grown through the submucosa into the muscularis propria
T₃	Tumour has grown through the muscularis propria into the subserosa but not to neighbouring organs or tissues
T₄	Tumour has spread completely through the colon or rectal wall and into nearby tissues or organs
N	Lymph node involvement
N_x	Lymph nodes cannot be assessed
N₀	No regional lymph node involvement is found
N₁	Cancer found in 1–3 nearby lymph nodes
N₂	Cancer found in 4 or more nearby lymph nodes
M	Metastasis
M_x	Presence of distant metastasis cannot be assessed
M₀	No distant metastasis seen
M₁	Distant metastasis present

TABLE 42-14 Classification systems used to stage colon cancer

* Staging system is based on TNM classification.

† See Box 42-14.

‡ Estimated 5-year survival rates.

Source: Adapted from DuBois RN. Neoplasms of the large and small intestine. In: Goldman L, Ausielo D, eds. Cecil textbook of medicine. 23rd edn. Philadelphia: Saunders; 2007.

Surgical therapy

Polypectomy during colonoscopy can be used to resect colorectal cancer in situ and is considered successful when the resected margin of the polyp is free of cancer, the cancer is well differentiated and there is no apparent lymphatic or blood vessel involvement. During surgery, if the cancer is localised, it can be resected together with a margin of healthy tissue on either side and the remaining cancer-free ends sewn back together. Nearby lymph nodes are also removed. Chemotherapy or radiation therapy is used if the cancer has spread to lymph nodes or into nearby tissue. Once the cancer has spread to distant sites (e.g. liver, lungs, peritoneum, ovaries) surgery is palliative.

Surgical goals include complete resection of the tumour together with adequate margins of healthy tissue, a thorough exploration of the abdomen to determine whether the cancer has spread, removal of all lymph nodes that drain the area where the cancer is located, restoration of bowel continuity so that normal bowel function will return and prevention of surgical complications. The optimal procedure is bowel resection with re-anastomosis of the remaining segments.

Reduction of colonic bacteria is necessary to decrease postoperative infection and breakdown at the site of anastomosis. In preparation for surgery, a bowel-cleansing agent is used to empty the bowel if there are anticipated problems with faecal loading that might cause technical difficulties with the procedure. A single preoperative dose of intravenous cephalosporin and metronidazole or gentamicin and metronidazole is strongly recommended to further decrease the amount of colonic and rectal bacteria. If the patient has a bowel obstruction or perforation, bowel cleansing is contraindicated. In this situation, the obstruction is relieved and a temporary colostomy is formed.

The site of the cancer dictates the site of the resection. For example, caecal cancer resection includes removal of a segment of terminal ileum and its mesentery and the right colon. The transverse colon is removed if the cancer is in the middle of the transverse colon. Right hemicolectomy is performed when the cancer is located in the caecum, ascending colon, hepatic flexure or transverse colon to the right of the middle colic artery. A left hemicolectomy involves resection of the left transverse colon, the splenic flexure, the descending colon, the sigmoid colon and the upper portion of the rectum. When the tumour is not resectable or if metastasis is present, palliative surgery is done to control haemorrhage or relieve an obstruction.

Clear margins are most difficult to obtain with rectal carcinoma. Location of the rectal lesion determines the surgical procedure to be performed. Unless sufficient rectum remains to ensure a secure anastomosis, an abdominal–perineal resection is indicated. Abdominal–perineal resection is most often performed when the cancer is located within 5 cm of the anus. In the abdominal–perineal resection, an abdominal incision is made and the proximal sigmoid is brought through the abdominal wall to form a permanent colostomy. The distal sigmoid, rectum and anus are removed through a perineal incision. The perineal wound may be closed around a drain or left open with packing to allow healing by granulation. Complications that can occur are delayed wound healing, haemorrhage, persistent perineal sinus tracts, infections, and urinary tract and sexual dysfunctions.

Low anterior resection may be indicated for tumours of the rectosigmoid and the mid-to-upper rectum. The use of end-to-end anastomosis (EEA) staplers has allowed lower and more secure anastomosis. The stapler is passed through the anus, where the colon is stapled to the rectum. This technique has made it possible to resect lesions as close as 5 cm to the anus.

Sphincter-sparing procedures are being performed for the patient with early disease. In these procedures a local resection is performed and the anal sphincters are left intact. The number of these procedures may increase with continued early detection and surveillance. Laparoscopic colectomy is being used with greater frequency. Benefits are faster return of bowel function, decreased incisional infections, shortened hospital stay and improved cosmetic appearance.

Chemotherapy

Chemotherapy is recommended when a patient has lymph node involvement at the time of surgery or has metastatic disease. Chemotherapy is used both as an adjuvant therapy following colon resection and as primary treatment for non-resectable colorectal cancer. At present, the combination of 5-fluorouracil plus leucovorin and either oxaliplatin or irinotecan is approved as first-line chemotherapy for patients with metastatic colorectal cancer. These regimens are known as FOLFOX and FOLFIRI, respectively. For patients who are not considered appropriate candidates for this triple therapy, acceptable alternative treatment protocols include the use of 5-fluorouracil with leucovorin or capecitabine either as a single agent or in combination with oxaliplatin.⁴⁶ Additional agents that are useful in metastatic disease include mitomycin, which can be combined with either capecitabine or 5-fluorouracil. (Chemotherapy drugs are discussed in Ch 15.)

Biological and targeted therapy

Targeted therapies used to treat colon cancer include two monoclonal antibodies. One drug targets epidermal growth factor receptor (cetuximab) and the other drug targets vascular endothelial growth factor (bevacizumab) (see Ch 15). Bevacizumab works by preventing the formation of new blood vessels, a process known as angiogenesis. At this time cetuximab is approved by the Therapeutic Goods Administration (TGA) to be used alone or in conjunction with other chemotherapeutic agents,⁴⁶ whereas bevacizumab can be used only in combination with the chemotherapy drugs 5-fluorouracil and irinotecan. (Biological and targeted therapy is discussed in Ch 15.) Clinical trials continue utilising biological and targeted therapies in both the adjuvant and metastatic settings.

Radiation therapy

Radiation therapy may be used pre- or postoperatively as an adjuvant to surgery and chemotherapy or as a palliative measure for patients with metastatic cancer. It is used preoperatively in rectal tumours to reduce the risk of local pelvic recurrence postoperatively. As a palliative measure, its primary objective is to reduce tumour size and provide symptomatic relief. (Radiation therapy is described in Ch 15.)

NURSING MANAGEMENT: COLORECTAL CANCER

Nursing assessment

Subjective and objective data that should be obtained from a patient with colorectal cancer are presented in Table 42-15.

TABLE 42-15 Colorectal cancer

NURSING ASSESSMENT

CT, computed tomography.

Planning

The overall goals are that the patient with colorectal cancer will have: (1) normal bowel elimination patterns; (2) a quality of life appropriate to the disease progression; (3) relief of pain; and (4) feelings of comfort and wellbeing.

Nursing implementation

Health promotion

The nurse can encourage all patients aged over 50 to have regular colorectal cancer screening. Screening for high-risk patients should begin before age 50, usually beginning with colonoscopy and continuing at intervals that vary according to risk factors. Participation in early cancer screening is effective in decreasing mortality but barriers exist, including lack of information and fear of diagnosis.

Colonoscopy detects polyps only when the bowel has been adequately prepared to eliminate stool. When screening is done in the outpatient setting, the nurse must teach the patient how to complete the bowel preparation. In the hospitalised patient, nurses have a more direct role in ensuring that the bowel cleansing preparation is followed. Various methods are used for emptying the bowel prior to colonoscopy, including a low-fibre diet for 48 hours or ingesting clear liquids only for 24 hours before the colonoscopy and then using one of the following oral preparations: a large-volume polyethylene glycol lavage solution, a smaller volume sodium picosulfate or a small-volume sodium phosphate liquid. Many patients find the large-volume polyethylene glycol lavage solution difficult to drink, and side effects include nausea and bloating. The sodium picosulfate or sodium phosphate liquid is easier to ingest but can cause fluid and electrolyte imbalance in patients with heart, kidney and liver disease. Patients also need to drink a large volume of clear fluid with these preparations.

Acute intervention

Preoperative care

Acute nursing care for the patient with a colon resection is similar to care of the patient having a laparotomy (see Ch 17). It is important for patient education to commence in the preoperative phase of care. Patients will need information about prognosis and future screening, as well as support dealing with the diagnosis of cancer. An abdominal–perineal resection results in closure of the anus and a permanent ostomy. If this is the planned surgical procedure, the patient will most likely need intense emotional support to cope with their prognosis and the radical change in body appearance and function. Patients who are at risk of needing a temporary or permanent ostomy should be referred preoperatively to the stoma nurse, for stoma siting, education and emotional support. Patients should be taught side-to-side positioning and proper positioning for taking a sitz bath.

Postoperative care

If the cancer was resected and the ends were re-anastomosed, bowel function is maintained and routine postoperative care is appropriate. After an abdominal–perineal resection, there are two wounds and a stoma. An abdominal incision is made through which the colon is resected, and an incision is made in the perineum. The management of a perineal incision differs depending on the type of wound. Three techniques are used: (1) packing of the entire open wound; (2) partial closure with Penrose drains for open drainage; and (3) primary closure of the perineal wound with closed-suction drainage of the pelvic cavity. The type of management of the perineal wound is individualised. The open and packed method is used in patients with extensive surgery or uncontrollable bleeding in the pelvic wound. When infection or contamination is minimal, a partial closure with drains is used. Low intermittent wall suction or Redivac suction are commonly used to drain the operative site during the early postoperative period. Drains remain in place until drainage is less than 50 mL per 24 hours, which usually occurs after 3–5 days.

A patient who has open and packed wounds requires meticulous postoperative care. The perineal dressing is reinforced and changed frequently during the first several hours postoperatively when drainage is likely to be most profuse. All drainage is carefully assessed for amount, colour and consistency. The drainage is usually serosanguineous.

The packing is usually left in place for 2–3 days because packing the pelvic cavity for prolonged periods may result in sepsis and rigidity of the cavity wall and thus impede the healing process. The nurse should examine the wound regularly and record bleeding, excessive drainage and unusual odour. The perineal wound is usually irrigated with a normal saline solution when the dressings are changed. Dressings are changed several times a day and aseptic technique is always used.

If the wound is partially closed and drains are in place, the nurse assesses the incision for suture integrity and signs and symptoms of wound inflammation and infection. The drainage is examined for amount, colour and characteristics. The area around the drain is observed for signs of inflammation and kept clean and dry. The nurse monitors for oedema, erythema and drainage around the suture line, fever and an elevated WBC. If the perineal wound was not closed, warm sitz baths for 10–20 minutes three to four times a day assist in tissue debridement, provide comfort and increase circulation to the area. Moist heat causes vasodilation, which allows more oxygen to flow to the affected area. Sitz baths of more than 20 minutes may result in too much vasodilation, causing congestion and discomfort.

The patient may complain of pain and itching in and around the wound, which can be treated with antipruritic agents and sitz baths. Use of a pressure-reducing chair cushion provides comfort when sitting. Sitting on a toilet for prolonged periods is discouraged until the perineal wound is well healed.

The patient may experience phantom rectal sensation because the sympathetic nerves responsible for rectal control are not severed during the surgery. The nurse must be astute in distinguishing phantom sensations from perineal abscess pain.

Sexual dysfunction is a possible complication of an abdominal–perineal resection. Although the likelihood of sexual dysfunction depends on the surgical technique used, the surgeon should discuss the possibility with the patient. Members of the healthcare team should be available to address the patient’s questions and concerns. Erection, ejaculation and orgasm involve different nerve pathways and a dysfunction of one does not mean complete sexual dysfunction. The stomal therapy nurse is an important source of information concerning sexual dysfunction resulting from an abdominal–perineal resection.

Ambulatory and home care

Psychological support for the patient and family is important. The recovery period is long, and the cancer could return. The overall 5-year survival rate for all patients undergoing resection for colorectal cancer is greater than 55%.⁴⁷ Recurrent cancer is painful, debilitating and demoralising, and patients need much emotional support. (The special needs of the cancer patient are discussed in Ch 15.) If the cancer is advanced, issues surrounding end-of-life preparation and hospice requirements may need to be addressed (see Ch 9).

The perineal wound may not be completely healed before discharge. After discharge the surgeon, community nurse and stomal therapy nurse in an outpatient clinic may be involved in wound management. The wound is usually irrigated and debrided. The skin around the wound should be assessed for loose hair. Shaving may be necessary to prevent the development of a chronic draining sinus. Continual drainage may indicate the presence of a foreign body, fistula or rectal tissue that was not removed during surgery. The patient and significant others should be taught management of the wound and the procedure to take a sitz bath at home. The patient and the family should be aware of all community services available for assistance.

Ostomy surgery

An ostomy is a surgical procedure that allows intestinal contents to pass from the bowel through an opening in the skin on the abdomen. The opening is called a stoma. The stoma is created when the intestine is brought through the abdominal wall and sutured to the skin. The intestinal contents then empty through the hole on the surface of the abdomen rather than being eliminated through the anus.

An ostomy is used when the normal elimination route is no longer possible. For example, if the person has colorectal cancer, the diseased portion must be removed together with a certain margin of healthy tissue. Sometimes the tumour can be resected leaving enough healthy tissue to immediately anastomose (reconnect) the two remaining ends of healthy bowel, and no ostomy is necessary. If the tumour involves the rectum and is large enough to necessitate the removal of the anal sphincters, the anus is sutured closed and a permanent ostomy is created.

Patients with high risk of colorectal cancer, such as those with FAP, may have a total colectomy. As discussed earlier, patients with ulcerative colitis may also need to have a total proctocolectomy. In both situations, the surgeon will form an ileal pouch anal anastomosis if the anal sphincters are not diseased and can be left intact. If not, the person will need to have a permanent ileostomy.

TYPES

Ostomies are described according to location and type (see Fig 42-11). An ostomy in the ileum is called an ileostomy, an ostomy in the sigmoid colon is called a sigmoid colostomy, an ostomy in the transverse colon is called a transverse colostomy and so on. The more distal the ostomy, the more the intestinal contents resemble faeces that is eliminated from an intact colon and rectum. Normally, water and electrolytes are reabsorbed from the faeces as it passes through the colon. Since output from an ileostomy has never entered the colon, it will be liquid and the ileostomy will drain continually. A bag must be worn constantly over the ileostomy to collect the drainage. In contrast, output from a sigmoid colostomy will resemble normal formed stool and some patients are able to regulate emptying time so they do not need to wear a collection bag. (See colostomy irrigations on p 1161.) A comparison of colostomies and ileostomies is shown in Table 42-16.

Figure 42-11 Types of ostomies.

TABLE 42-16 Comparison of ileostomy and colostomies

The major types of ostomies are end stoma, loop stoma and double-barrel stoma.

End stoma

An end stoma is surgically constructed by dividing the bowel and bringing out the proximal end as a single stoma. The distal portion of the GI tract is surgically removed, or the distal segment is oversewn and left in the abdominal cavity with its mesentery intact. An end colostomy or ileostomy is then constructed. When the distal bowel is oversewn rather than removed, the procedure is known as a Hartmann’s pouch (see Fig 42-12). If the distal bowel is removed, the stoma is permanent. If the distal bowel remains intact and oversewn, the potential exists for the bowel to be reanastomosed and the stoma to be closed.

Figure 42-12 Sigmoid colostomy. The distal bowel is oversewn and left in place to create a Hartmann’s pouch.

Loop stoma

A loop stoma is constructed by bringing a loop of bowel to the abdominal surface and then opening the anterior wall of the bowel to provide faecal diversion. This results in one stoma with a proximal and distal opening and an intact posterior wall that separates the two openings. The loop of bowel is frequently held in place with a plastic rod for 7–10 days after surgery to prevent it from slipping back into the abdominal cavity (see Fig 42-13). A loop stoma is usually temporary.

Figure 42-13 Loop colostomy.

Double-barrel stoma

When the bowel is divided, both the proximal and distal ends are brought through the abdominal wall as two separate stomas (see Fig 42-11). The proximal one is the functioning stoma; the distal, non-functioning stoma is referred to as the mucous fistula. A double-barrel stoma is usually temporary.

Ileoanal reservoir

As previously described in this chapter, this procedure involves proctocolectomy and ileoanal anastomosis with the formation of an ileal reservoir (see Fig 42-4).

NURSING MANAGEMENT: OSTOMY SURGERY

Two major aspects of nursing care are: (1) emotional support as the patient copes with a radical change in body image; and (2) patient teaching about the many aspects of stoma care and the ostomy. Control of bowel elimination occurs by about the age of 2; most people consider bowel elimination a private matter and the accompanying sounds and smells embarrassing. People with ostomies lose control over defecation and worry about odour and leakage of faeces from around the bag. Quality of life is usually affected.⁴⁸ People with new ostomies may be reluctant to return to work and avoid situations where they are around other people. Since drainage of faeces into a bag on the abdomen makes them feel unattractive to their partners, they may be unwilling to engage in sexual activities. However, with emotional support and education, patients can learn to manage the ostomy, return to their previous lifestyle and regain a high quality of life.

Preoperative care

Major aspects of preoperative care that are unique to ostomy surgery include: (1) psychological preparation for the ostomy; (2) selection of a flat site on the abdomen that allows secure attachment of the collection bag; and (3) selection of a stoma site that will be clearly visible to the patient who will be taking care of it. Psychological preparation and emotional support are particularly important as the patient copes with the change in body image, the loss of control over elimination and the odours. Providing opportunities for patients to state their concerns and have questions answered in understandable terms enhances patients’ feelings of control and thus their ability to cope.

The stomal therapy nurse selects the site where the ostomy should be positioned and marks the abdomen preoperatively. The surgeon uses these markings as a guideline but may need to make adjustments based on the individual’s internal anatomy. Criteria for site selection include that it lies within the rectus muscle, is a flat, crease-free surface and is in the patient’s visual field. Stomas placed outside the rectus muscle increase the chance of developing a hernia. A flat site makes it much easier to create a good seal and avoid leakage from the bag. Patients who cannot see the stoma are unable to care for it.

The patient and family usually have many questions concerning the procedure. Ideally, they will be able to consult the stomal therapy nurse. The nurse determines the patient’s ability to perform self-care, identifies support systems and determines potential adverse factors that could be modified to facilitate learning during rehabilitation. Preoperative assessment must be comprehensive and include physical, psychological, social, cultural and educational components. The patient and family should understand the extent of surgery, the type of stoma and its care.

If the patient needs a referral, a trained ostomy visitor may be able to provide psychological support. This gives the patient and family an opportunity to meet someone who has adjusted well to an ostomy and who has experienced some of the same feelings and concerns that they have.

Bowel preparation is used to empty the intestines before surgery if there are anticipated problems with faecal loading that might cause technical difficulties with the procedure in order to decrease the chance of a postoperative infection due to bacteria in the faeces. A single preoperative dose of intravenous cephalosporin and metronidazole or gentamicin and metronidazole is strongly recommended to further decrease the amount of colonic and rectal bacteria.

Postoperative care

Postoperative nursing care includes assessment of the stoma and provision of an appropriate pouching system that protects the skin and contains drainage and odour. The nurse helps the patient to cope with the stoma and with the underlying disease that led to stoma formation, provides information, teaches practical stoma care techniques and helps address issues surrounding social interactions, employment, body image and sexuality. The stomal therapy nurse is specially trained to help patients in these areas, but all nurses working with patients who have had ostomies should develop the knowledge and skills to help them.

The stoma should be pink. A dusky blue stoma indicates ischaemia and a brown–black stoma indicates necrosis. The nurse should assess and document stoma colour every 8 hours. There is mild-to-moderate swelling of the stoma in the first 2–3 weeks after surgery (see Table 42-17).

TABLE 42-17 Characteristics of stoma

* Sustained colour changes must be reported to the surgeon.

† Closely observe and report to the surgeon and adjust the stoma opening size in the pouch.

‡ Report moderate-to-large amounts of bleeding to surgeon.

An appropriate pouching system is vital for protecting the skin and providing dependable drainage collection. The pouching system consists of a skin barrier and a bag or pouch to collect the faeces. The skin barrier is a piece of pectin-based or karaya wafer that has a measurable thickness and hydrocolloid adhesive properties. The adhesion occurs in two phases. First, the wafer’s backing has adhesive material that forms an immediate bond with the skin. Later, the hydrocolloids interface with the moisture on the skin to form a tighter seal. The skin barrier remains in place for about 5–7 days. The length of adhesion depends on factors such as the strength of the seal and the amount of drainage from the stoma. If the abdominal stoma site has bends or creases, it is difficult to get a good seal and the skin barrier will pull away faster. Also, the weight of drainage from the stoma pulls the wafer away from the skin. For this reason, ostomy bags should be emptied when two-thirds full.

The pouch must be compatible with the patient’s abdominal contours. A flat pouch is used for a flat abdominal surface and a convex pouching system is used when the stoma is located in a concave plane. Pouches come as one- or two-piece systems. The one-piece system has the skin barrier attached, and the two-piece system allows removal of the pouch without removing the skin barrier. The skin should be washed with mild soap, rinsed with warm water and dried thoroughly before the barrier is applied. Vigorous cleaning with strong soaps will damage the skin. A plasticising skin sealant (e.g. protective skin barrier wipes) can be applied to the skin before the skin barrier to protect the skin from stripping when removing the pouch base. With an open-ended, transparent, plastic, odour-proof pouch, it is easy to protect the skin and to observe and collect the drainage. The pouch must fit snugly to prevent leakage around the stoma. The size of the stoma is determined with a stoma-measuring card. Although the pouch is applied after surgery, the colostomy functions when peristalsis has been adequately restored. When a temporary colostomy is performed and the stoma is opened in the operating room with no bowel preparation being done previously, the stoma functions immediately.

The volume, colour and consistency of the drainage should be recorded. Each time the pouch is changed, the condition of the skin should be observed for irritation.

The patient should be able to perform a pouch change, provide appropriate skin care, control odour, care for the stoma and identify signs and symptoms of complications. The patient should know the importance of fluids and a healthy diet and know when to seek healthcare advice. Home care and outpatient follow-up by the stomal therapy nurse is highly recommended. Patients should be discharged with written information about their particular ostomy, instructions for pouch changes, a list of supplies and where to purchase them (including names and telephone numbers of retailers), outpatient follow-up appointments with the surgeon and stomal therapy nurse, and the telephone numbers of the surgeon and nurse. Patient and family teaching guidelines are included in Box 42-15.

BOX 42-15 Ostomy self-care

PATIENT & FAMILY TEACHING GUIDE

Patients and their families must be able to do the following:

1. Explain what an ostomy is and how it functions.

2. Describe the underlying condition that resulted in the need for an ostomy.

3. Perform the following activities:

• remove the old skin barrier, cleanse the skin and correctly apply new skin barriers

• apply, empty, clean and remove the pouch

• empty the pouch before it is two-thirds full to prevent leakage

• irrigate colostomy to regulate bowel elimination (optional).

4. Explain how to contact the stomal therapy nurse with questions.

5. Describe how to obtain additional ostomy supplies.

6. Explain dietary and fluid management.

• Identify a well-balanced diet and dietary supplements to prevent nutritional deficiencies.

• Identify foods to avoid/reduce diarrhoea, gas or obstruction (with ileostomy).

• Drink at least 2 L/day of fluid to prevent dehydration (unless contraindicated).

• Increase fluid intake during hot weather, excessive perspiration and diarrhoea to replace losses and prevent dehydration.

• Describe symptoms of fluid and electrolyte imbalance.

• Explain how to contact the registered dietician with questions.

• Explain how to recognise problems (fluid and electrolyte deficits, fever, diarrhoea, skin irritation, stomal problems and contact the appropriate healthcare provider).

7. Describe community resources to assist with emotional and psychological adjustment to the ostomy.

8. Explain the importance of follow-up care.

9. Describe the ostomy’s potential effects on sexual activity, social life, work and recreation, and strategies to manage these influences.

Teaching is often complicated by the patient’s emotional responses to the stoma. Emotional support, interventions from skilful stomal therapy nurses and visits from people who have successfully learned to manage their ostomies will help patients learn to cope with and manage the new stoma.

Colostomy care

Nursing care for the patient with a colostomy is presented in NCP 42-3.

NURSING CARE PLAN 42-3 The patient with a colostomy/ileostomy

IV, intravenous.

A colostomy in the ascending and transverse colon has semiliquid stools. The patient needs to be instructed to use a drainable pouch. A colostomy in the sigmoid or descending colon has semiformed or formed stools and can sometimes be regulated by the irrigation method. The patient may or may not wear a drainage pouch. Pouches should have a gas filter.

A well-balanced diet and adequate fluid intake are important and most patients with colostomies can eat anything they choose. However, dietary modifications are helpful for decreasing gas production and odour. Colonic bacteria act on certain poorly digested carbohydrates to form gas. Major gas-producing foods include beans, cabbage, cauliflower, brussel sprouts, broccoli and asparagus. Potatoes, corn, noodles and wheat also produce gas, but rice does not. The time between ingestion of gas-producing food and actual flatulence is approximately 6–8 hours for the patient with a distal colostomy. Box 42-16 lists various foods and their effects on stoma output.

Colostomy irrigations

Colostomy irrigations are used to stimulate emptying of the colon in order to achieve a regular bowel pattern. If control is achieved, there should be little or no spillage between irrigations. The patient who establishes regularity may need to wear only a pad or small pouch over the stoma. The patient who cannot or chooses not to establish regularity by irrigations must wear a pouch at all times. Regularity is only possible when the stoma is in the distal colon or rectum. Irrigations are not used for more proximal ostomies. The procedure for colostomy irrigation is presented in Box 42-17.

BOX 42-17 Colostomy irrigation

PATIENT & FAMILY TEACHING GUIDE

Procedure

1. Place 500–1000 mL of lukewarm water (not exceeding 37°C) in the container. The volume is titrated for the individual; use enough irrigant to distend the bowel but not enough to cause cramping pain. Most adults use 500–1000 mL of water.

2. Ensure comfortable position. The patient may sit in a chair in front of the toilet or on the toilet if the perineal wound is healed.

3. Clear tubing of all air by flushing it with fluid.

4. Hang the container on a hook or IV pole (40–55 cm) above the stoma (about shoulder height).

5. Apply irrigating sleeve and place the bottom end in the toilet bowl.

6. Lubricate the stoma cone, insert the cone tip gently into the stoma and hold the tip securely in place.

7. Allow irrigation solution to flow in steadily for 5–10 minutes.

8. If cramping occurs, stop the flow of solution for a few seconds, leaving the cone in place.

9. Clamp the tubing and remove irrigating cone when the desired amount of irrigant has been delivered or when the patient senses colonic distension.

10. Allow 30–45 minutes for the solution and faeces to be expelled. Initial evacuation is usually complete in 10–15 minutes. Close off the irrigating sleeve at the bottom to allow ambulation.

11. Clean, rinse and dry the peristomal skin well.

12. Replace the colostomy drainage pouch or desired stoma covering.

13. Wash and rinse all equipment and hang to dry.

IV, intravenous.

All equipment should be assembled before the irrigation. A commercially obtained irrigation set usually has all the equipment needed. The nurse should encourage the patient to watch the procedure and should explain each step to the patient. The cone tip on the tubing controls the depth of insertion and prevents the water from coming out from the stoma and not going into the colon. If resistance is met, force should not be used because perforation of the intestine can result. However, this is unlikely when using a stoma cone. A hard plastic catheter is not recommended because of the risk of intestinal perforation. The procedure should not be rushed; the patient should feel relaxed. The patient or family member must be instructed in the procedure and must be able to demonstrate how to do it. This can be done in the outpatient setting.

Ileostomy care

Care of the ileostomy is presented in NCP 42-3. An ileostomy stoma protrusion of at least 1–1.5 cm makes care easier. When the stoma is flat, seepage occurs, resulting in altered skin integrity. Drainage is frequent and extremely irritating to the skin. Since regularity cannot be established, a pouch must be worn at all times. An open-ended, drainable pouch is preferable because drainage can be emptied easily. The drainable pouch is usually worn for 4–7 days before being changed unless leakage occurs. In that case, the pouch should be promptly removed, the skin cleansed and a new pouch applied. A solid skin barrier should always be used. A transparent pouch should be used in the initial postoperative period to facilitate assessment of stoma viability and ease of pouch application by the patient.

Immediately after surgery, the patient should be observed for signs and symptoms of fluid and electrolyte imbalance, particularly potassium, sodium and fluid deficits. In the first 24–48 hours after surgery the amount of drainage from the stoma may be negligible. People with new ileostomies lose the absorptive functions provided by the colon and the delay provided by the ileocaecal valve. As a result, they may experience a period of high-volume output of 1000–1800 mL per day when peristalsis returns. Later on, the average amount can be 500 mL daily because the proximal small bowel adapts. If the small bowel has been shortened as a result of surgical resections, the drainage from the ileostomy may be greater. The patient needs to increase fluid intake to 2–3 L of fluid daily and pay particular attention to excessive fluid losses from heat and sweating. Patients must learn the signs and symptoms of fluid and electrolyte imbalance so that they can take appropriate action. Because ileostomy output contains significant amounts of sodium and potassium, fluid intake should include liquids containing electrolytes.

A low-fibre diet is ordered initially, and fibre-containing foods are reintroduced gradually. The ileostomy patient is susceptible to obstruction because the lumen is less than 2.5 cm in diameter and may narrow further at the point where the bowel passes through the fascia/muscle layer of the abdomen. Foods such as coconuts, mushrooms, olives, stringy vegetables, foods with skins, dried fruits and meats with casings must be chewed extremely well so that they are very small when swallowed. The goal for the patient is a return to a normal, pre-surgical diet.

The stoma may bleed easily when it is touched because it has a high vascular supply. The patient should be told that minimal oozing of blood is normal. If the terminal ileum has been removed, the patient may need vitamin B₁₂ injections.

Adaptation to an ostomy

Adaptation to the ostomy is a gradual process. The patient experiences a grief reaction from the loss of a body part and an alteration in body image. The adjustment period is unique to each individual. Psychological support is needed during the grieving process. Patients have concerns about body image, sexual activity, family responsibilities and changes in lifestyle. The patient may become resentful and have fears of odour or soiling. Supportive measures include encouraging the patient to share their concerns and ask questions, providing information in a manner that is easily understood by the patient, recommending support services, and helping the patient to develop confidence and competence in managing the stoma. The nurse provides support by responding to the physiological needs of stoma care and the psychosocial need for self-esteem.

Activities of daily living are resumed within 6–8 weeks. Heavy lifting should be avoided. The patient’s physical condition determines when sports may be resumed. Patients must know that they cannot participate in sports where direct trauma to the stoma is likely. Water does not harm the stoma, although the patient should be advised to swim with the pouch in place.

Sexual dysfunction after ostomy surgery

Discussion of sexuality and sexual function must be incorporated in the plan of care. The nurse can help the patient understand that sexual function or sexual activity may be affected but that sexuality does not have to be altered.

Pelvic surgery can disrupt nerve and vascular supply to the genitals. Radiation, chemotherapy and medications can also alter sexual function. The overall physical health of the patient influences sexual desire. Generalised fatigue caused by illness can also influence desire. By communicating this information to patients, they can plan sexual activity around a drug schedule and energy levels. Any pelvic surgery that removes the rectum has the potential of damaging the parasympathetic nerve plexus. Erection in men depends on the parasympathetic nerves that control blood flow and vascular supply to the pelvis and the pudendal nerves that transmit sensory responses from the genital area. Nerve-sparing surgical techniques are used when possible to preserve sexual function. Radiation therapy to the pelvis can reduce blood flow to the pelvis by causing scarring in the small blood vessels. Radiation therapy can also affect vaginal expansion and lubrication. Pelvic surgery usually does not affect a woman’s arousal unless part of or the entire vagina is removed. Muscle contraction and genital pleasure that occur during orgasm are not disrupted by pelvic surgery. If the sympathetic nerves in the male’s presacral area are damaged, ejaculation may be disrupted. This can occur with an abdominal–perineal resection. Orgasms can occur in both men and women who have had stoma surgery, although other aspects of the sexual response may be affected.

The psychological impact of the stoma and how it affects the patient’s body image and self-esteem must be discussed. Emotional factors can contribute to sexual problems. A life-threatening illness can override concerns about sexual function. The nurse assists patients to identify ways of coping with depression and anxiety resulting from illness, surgery or postoperative problems.

The social impact of the stoma is interrelated with the psychological, physical and sexual aspects. Concerns of people with stomas include the ability to resume sexual activity, altering clothing styles, the effect on daily activities, sleeping while wearing a pouch, passing gas, the presence of odour, cleanliness and deciding when or if to tell others about the stoma. The fear of rejection from a partner or the fear that others will not find them desirable as a sexual partner can be a concern. The nurse should encourage open communication about feelings and should realise that patients need time to adjust to the pouch and to body changes before feeling secure in their sexual functioning.

Although pregnancy is possible, the healthcare provider may recommend a limited number of pregnancies on the basis of the patient’s physical condition. The person with an ostomy who becomes pregnant should have regular medical care.

Diverticulosis and diverticulitis

A diverticulum is a saccular dilation or outpouching of the mucosa through the circular smooth muscle of the intestinal wall (see Figs 42-14 and 42-15). Diverticula may occur at any point within the GI tract but are most commonly found in the sigmoid colon. Clinically, diverticular disease covers a spectrum from asymptomatic, uncomplicated diverticulosis to diverticulitis with complications such as perforation, abscess, fistula and bleeding. Multiple non-inflamed diverticula are present in diverticulosis. Diverticulitis is an infection of the diverticular sacs that is thought to be caused by obstruction with faecal matter. In diverticulitis, inflammation of the diverticula occurs, which can result in perforation of one or more diverticula.

Figure 42-14 Diverticula are outpouchings of the colon. When they become inflamed, the condition is diverticulitis. The inflammatory process can spread to the surrounding area in the intestine.

Figure 42-15 In diverticular disease, the outpouches (arrows) of mucosa appear as slit-like openings from the mucosal surface of the open bowel.

AETIOLOGY AND PATHOPHYSIOLOGY

Diverticular disease is a common disorder that affects 5% of the population by the age of 40 years and 65% by the age of 85 years.⁴⁹ Since most cases of diverticulosis are asymptomatic, it is difficult to calculate the true prevalence of the disease.

Diverticula in the left (descending, sigmoid) colon are prevalent in European populations, whereas diverticula in the right (ascending) colon occur more commonly in Asian populations and younger patients.⁵⁰ The aetiology of diverticulosis of the ascending colon is unknown, but diverticula in the sigmoid colon are thought to be associated with high luminal pressures from a deficiency in dietary fibre intake and perhaps combined with a loss of muscle mass and collagen with the ageing process. The disease is more prevalent in developed, industrialised populations that consume diets low in fibre and high in refined carbohydrates, and it is virtually unknown in areas of the world such as rural Africa, where high-fibre diets are consumed. The incidence of diverticulosis rises with increasing age and is associated with obesity in people under the age of 40.⁵¹

Diverticulitis results from the retention of stool and bacteria in the diverticulum, forming a hardened mass called a faecalith. This causes inflammation and usually small perforations. Inflammation of the diverticulum spreads to the surrounding area in the intestines (see Fig 42-16), causing the tissue to become oedematous.

Figure 42-16 Complications of diverticulitis.

Asymptomatic diverticular disease is typically diagnosed on routine sigmoidoscopy or colonoscopy. Symptomatic diverticular disease can be further broken down into painful diverticular disease and diverticulitis.

CLINICAL MANIFESTATIONS

The majority of patients with diverticulosis have no symptoms. Those with symptoms typically have abdominal pain and/or changes in bowel habits, but no symptoms of inflammation. Approximately 15% of patients with diverticulosis progress at some point in time to acute diverticulitis. In patients with diverticulitis, abdominal pain is localised over the involved area of the colon. The most common symptoms of diverticulitis in the sigmoid colon include left lower quadrant abdominal pain, fever, leucocytosis and sometimes a palpable abdominal mass. Elderly patients with diverticulitis may be afebrile, with a normal WBC and little, if any, abdominal tenderness.

Complications of diverticulitis include perforation with peritonitis, abscess and fistula formation, bowel obstruction, ureteral obstruction and bleeding. Bleeding can be extensive but usually stops spontaneously. Diverticulitis is the most common cause of lower gastrointestinal haemorrhage.⁵⁰

DIAGNOSTIC STUDIES

Initial studies for suspected diverticulosis include an FBC, urinalysis, supine and upright radiographs of the abdomen and physical examination. Ultrasound and CT scan with contrast may then be used to confirm the diagnosis and evaluate the severity of the disease (see Box 42-18). A barium enema is sometimes used to determine narrowing or obstruction of the colonic lumen. A colonoscopy may be performed to rule out polyps or lesions. A patient with acute diverticulitis should not have a barium enema or colonoscopy because of the possibility of perforation and peritonitis.

BOX 42-18 Diverticulosis and diverticulitis

MULTIDISCIPLINARY CARE

Diagnostic studies

History and physical examination

Testing of stool for occult blood

NURSING AND COLLABORATIVE MANAGEMENT: DIVERTICULOSIS AND DIVERTICULITIS

A high-fibre diet, mainly from fruits, vegetables and cereals, and a decreased intake of fat and red meat are recommended for preventing diverticular disease. High levels of physical activity also seem to decrease the risk.⁵⁰ Bulking agents such as psyllium hydrophilic mucilloid may be used. Increase in fibre intake should be accompanied by an increase in fluid intake. A high-fibre diet is also recommended once diverticular disease is present, although its benefits are unclear (see Table 42-5).

In acute diverticulitis, the goal of treatment is to allow the colon to rest and the inflammation to subside. The patient is kept on NBM status, given parenteral fluids and observed for signs of peritonitis. Broad-spectrum antibiotic therapy is required. The WBC is monitored. Frequently, diverticulitis can be managed in an outpatient setting, and hospitalisation is reserved for the elderly or those with severe symptoms.

When the acute attack subsides, oral fluids are given first and then the diet is progressed to semisolids. If the patient has a bowel resection or colostomy, the nursing care is the same as for these procedures.

Although diverticular disease is common, complications are rare. Bowel rest and antibiotic therapy are usually adequate. Surgery is reserved for patients with complications such as an abscess or an obstruction that cannot be managed medically. The usual surgical procedures involve resection of the involved colon with either a primary anastomosis if adequate bowel cleansing is feasible or a temporary end colostomy. Intestinal continuity can be restored once all inflammation and/or infection has resolved.⁵¹

The patient should be provided with a full explanation of the condition. Patients who understand the disease process well and adhere to the prescribed regimen are less likely to experience an exacerbation of the disease and its complications.

Hernias

A hernia is a protrusion of a viscus through an abnormal opening or a weakened area in the wall of the cavity in which it is normally contained. A hernia may occur in any part of the body, but it usually occurs within the abdominal cavity. Hernias that easily return to the abdominal cavity are called reducible. The hernia can be reduced manually or may reduce spontaneously when the person lies down. If the hernia cannot be placed back into the abdominal cavity, it is known as irreducible, or incarcerated. In this situation the intestinal flow may be obstructed. When the hernia is irreducible and the intestinal flow and blood supply are obstructed, the hernia is strangulated. The result is an acute intestinal obstruction.

Types

The inguinal hernia is the most common type of hernia and occurs at the point of weakness in the abdominal wall where the spermatic cord in men and the round ligament in women emerge (see Fig 42-17). When the protrusion escapes through the inguinal ring and follows the spermatic cord or the round ligament, it is termed an indirect hernia. When it escapes through the posterior inguinal wall, it is a direct hernia. An inguinal hernia is more common in men.

Figure 42-17 A, Types of hernias. B, Indirect inguinal hernia.

A femoral hernia occurs when there is a protrusion through the femoral ring into the femoral canal. It occurs below the inguinal (Poupart’s) ligament as a bulge. It becomes strangulated easily and occurs more often in women. An umbilical hernia occurs when the rectus muscle is weak (as with obesity) or when the umbilical opening fails to close after birth.

Ventral or incisional hernias are due to weakness of the abdominal wall at the site of a previous incision. They occur most commonly in patients who are obese, have had multiple surgical procedures in the same area or have had inadequate wound healing because of poor nutrition or infection.

CLINICAL MANIFESTATIONS

A hernia may be readily visible, especially when the person tenses the abdominal muscles. There may be some discomfort as a result of tension. If the hernia becomes strangulated, the patient will experience severe pain and symptoms of a bowel obstruction, such as vomiting, cramping abdominal pain and distension.

NURSING AND COLLABORATIVE MANAGEMENT: HERNIAS

Diagnosis is based on the history and physical examination findings. Surgery is the treatment of choice for hernias and prevents strangulation. Treatment of hernias is by laparoscopic surgery. The surgical repair of a hernia is known as a herniorrhaphy and usually requires only a short-term hospital stay. The reinforcement of the weakened area with wire, fascia or mesh is known as a hernioplasty. Strangulated hernias are treated immediately with resection of the involved area or a temporary colostomy so that necrosis and gangrene do not occur.

Some patients with hernias wear a truss, a pad placed over the hernia and held in place with a belt. The truss is worn to keep the hernia from protruding. If the patient wears a truss, the nurse should check for skin irritation caused by the continual rubbing of the truss against the skin.

After a hernia repair, the patient may have difficulty voiding. Therefore, the nurse should observe for a distended bladder. An accurate intake and output record is important. Scrotal oedema is a painful complication after an inguinal hernia repair. A scrotal support with application of an ice bag may help relieve pain and oedema. Coughing is not encouraged, but deep breathing should be done. If the patient needs to cough or sneeze, the incision should be splinted during coughing, and sneezing should be done with the mouth open. After discharge the patient may be restricted from heavy lifting for 6–8 weeks.

MALABSORPTION SYNDROME

Malabsorption results from the impaired absorption of fats, carbohydrates, proteins, minerals and vitamins. The stomach, small intestine, liver and pancreas regulate normal digestion and absorption. Digestive enzymes ordinarily break down nutrients so that absorption can take place through the intestinal mucosa and nutrients can get into the bloodstream. If there is an interruption in this process at any point, malabsorption may occur. Several problems can cause malabsorption (see Box 42-19). These can be classified into malabsorption caused by: (1) biochemical or enzyme deficiencies; (2) bacterial proliferation; (3) disruption of small intestine mucosa; (4) disturbed lymphatic and vascular circulation; or (5) surface area loss. Lactose intolerance, IBD, coeliac disease, tropical sprue and cystic fibrosis are all conditions that can result in malabsorption.

The most common clinical manifestation of fat malabsorption is steatorrhoea (bulky, foul-smelling, yellow–grey, greasy stools with putty-like consistency; see Table 42-18). Steatorrhoea does not occur with lactose intolerance.

TABLE 42-18 Clinical manifestations of malabsorption

Screening tests that are available for malabsorption include qualitative examination of stool for fat (Sudan stain), a 72-hour stool collection for quantitative measurement of faecal fat, and the D-xylose absorption–excretion test, which is a good screening test for carbohydrate absorption. Other diagnostic studies include three different kinds of breath tests: (1) the bile acid breath test, which is used to evaluate bile salt malabsorption or malabsorption from bacterial overgrowth; (2) the triolein breath test, which measures carbon dioxide excretion after ingestion of a radioactive triglyceride; and (3) the lactose hydrogen breath test, which is a sensitive, specific and non-invasive test for the detection of lactase deficiency. The rationale for the hydrogen breath test is that undigested lactose produces hydrogen when metabolised by bacteria in the colon and the hydrogen is excreted via the lungs.

A pancreatic secretion test may be performed to rule out pancreatic insufficiency. Endoscopy may be used to obtain a small bowel biopsy specimen for the diagnosis of coeliac disease or dissacharide deficiencies such as lactase. A small bowel barium enema is often performed to identify abnormal mucosal patterns. Capsule endoscopy can be used to assess the small intestine for malabsorption problems.

Laboratory studies that are frequently ordered include an FBC, measurement of prothrombin time (to see whether vitamin K absorption is adequate), serum vitamin A and carotene levels, serum electrolytes, cholesterol and calcium.

Coeliac disease

Until recently, coeliac disease was considered a relatively rare intestinal disease that began in childhood and was accompanied by symptoms of diarrhoea, malabsorption and malnutrition. It is now known that it is a common disease that occurs at all ages and can affect multiple body systems besides its primary site in the intestines.^52,⁵³ Coeliac sprue and gluten-sensitive enteropathy are other names for coeliac disease.⁵³ It is not the same disease as tropical sprue, which is a chronic disorder acquired in tropical areas that is characterised by progressive disruption of jejunal and ileal tissue, resulting in nutritional difficulties. Tropical sprue is treated with folic acid and tetracycline.

The incidence of coeliac disease is thought to be anywhere from 1 in 1500 to 1 in 133 people.⁵³ Most patients with coeliac disease are discovered during screening of high-risk groups.⁵⁴ High-risk groups include first- or second-degree relatives of someone with coeliac disease and people with disorders associated with the disease. The mean age at diagnosis is the mid-40s. It is slightly more common in women and symptoms often begin in childhood.⁵²

AETIOLOGY AND PATHOPHYSIOLOGY

Three factors that are necessary for the development of coeliac disease include genetic predisposition, gluten ingestion and an immune-mediated response.⁵³ About 90% of patients with coeliac disease have the human leucocyte antigen (HLA) allele HLA-DQ2 and the other 10% have HLA-DQ8. HLA type does not appear to influence the disease severity and not everyone with these genetic markers develops the disease.⁵²

As with other autoimmune diseases, the tissue destruction that occurs with coeliac disease is the result of chronic inflammation. Inflammation is activated by the ingestion of gluten found in wheat, rye and barley. A portion of the poorly digested gluten, called the gliadin fraction, makes its way from the small intestine’s lumen into the lamina propria. Gliadin-containing molecules bind to specific receptors in the lamina propria and stimulate antibody production. The antibodies then activate the release of cytokines, including interferon, interleukin-4 and TNF. The cytokines destroy the microvilli and brush border of the small intestine. This ultimately decreases the amount of surface area available for nutrient absorption. Malabsorption can be so severe that the person develops malnutrition and wasting. Poor calcium and vitamin D absorption can lead to decreased bone density and osteoporosis. Poor nutrition leads to anaemia and reproductive problems. The inflammation lasts as long as gluten ingestion continues. Treatment with a gluten-free diet halts the process.^53,⁵⁴ Most patients recover completely within 3–6 months of treatment but need to maintain a gluten-free diet for life.⁵³

If the disease is untreated and chronic inflammation continues unabated, epithelial cell proliferation at the area of destruction leads to crypt hyperplasia and reduced enterocyte differentiation. This process can lead to lymphoma.^53,⁵⁴ Adenocarcinoma of the small intestine is also associated with coeliac disease.⁵⁴

CLINICAL MANIFESTATIONS

Coeliac disease was first recognised in infants who had symptoms of foul-smelling diarrhoea, abdominal distension, anorexia, wasting and failure to thrive that appeared at about the time the baby was started on cereal. Adults have different symptoms from the classic symptoms observed in infants. Diarrhoea occurs in less than half of all patients with coeliac disease. Some people have no symptoms and the disease is only discovered during screening. Others have atypical symptoms such as decreased bone density and osteoporosis, dental enamel hypoplasia, iron, folate and fat-soluble vitamin deficiencies, peripheral neuropathy and reproductive problems.^52,⁵⁴ A vesicular skin lesion, dermatitis herpetiformis, is sometimes present. Coeliac disease is also associated with autoimmune diseases, particularly rheumatoid arthritis, type 1 diabetes mellitus and thyroid disease. The relationship between coeliac disease and other autoimmune diseases is not well understood. However, rheumatoid arthritis symptoms have disappeared in some cases when patients switched to a gluten-free diet.⁵⁴

Early diagnosis and treatment can prevent complications such as cancer (e.g. intestinal lymphoma), osteoporosis and possibly other autoimmune diseases. Screening is recommended for close relatives of patients known to have the disease, young patients with decreased bone density, those with anaemia once other causes are ruled out and certain autoimmune diseases.⁵³

DIAGNOSTIC STUDIES AND MULTIDISCIPLINARY CARE

Diagnosis of coeliac disease is confirmed by histological examination of biopsies taken from the duodenum and proximal small intestine. Serological testing is available and offers good sensitivity and specificity. IgA tissue transglutaminase antibody, using human recombinant protein as the antigen, is currently considered the most reliable serological test,⁵⁴ but a combination of serological tests may be used.⁵³ False positives and negatives are possible so histological evidence remains the gold standard for confirming the diagnosis. Biopsies show flattened mucosa and noticeable losses of villi.⁵³

Coeliac disease should be ruled out during a diagnostic analysis of IBS, since the symptoms are similar. Many people spend years seeking treatment for non-specific complaints before coeliac disease is eventually diagnosed—thus the large number of people who are diagnosed in adulthood.

Coeliac disease is treated with life-long avoidance of dietary gluten (see Box 42-20). Wheat, barley, oats and rye products must be avoided. Although pure oats do not contain gluten, oat products can become contaminated with wheat, rye and barley during the milling process. Gluten is also found in many food additives, preservatives and stabilisers. A combination of corticosteroids and a gluten-free diet is used to treat individuals with refractory coeliac disease who do not respond to the gluten-free diet alone. Maintenance of a gluten-free diet is difficult, particularly when travelling or eating in restaurants. The patient needs to know where to purchase gluten-free products. Gluten-free products are sold in health food stores and are available through various internet sites. Information and support can be obtained from the Coeliac Society of Australia (which has branches in most states) or the Coeliac Society of New Zealand (see Resources on p 1175). The nurse needs to continuously encourage and motivate patients to continue the gluten-free diet. Patients need to know that the intestinal damage will recur unless they adhere to the diet and that chronic inflammation can lead to complications such as lymphoma.⁵³

BOX 42-20 Coeliac disease

NUTRITIONAL THERAPY

^*Food labels should be read to detect the presence of gluten stabilisers or ingredients that contain gluten.

Lactase deficiency

Lactase deficiency is a condition in which the lactase enzyme is deficient or absent. Lactase is the enzyme that breaks lactose down into two simple sugars—glucose and galactose. Primary lactase insufficiency is most commonly due to genetic factors. Certain ethnic groups, especially those with Asian or African ancestry, develop low lactase levels at about the age of 5. Less common causes include low lactase levels due to premature birth and congenital lactase deficiency, a rare genetic disorder. Lactose malabsorption can also occur when conditions leading to bacterial overgrowth promote lactose fermentation in the small bowel, and when intestinal mucosal damage interferes with absorption.⁵⁵ Diseases in which the mucosa has been damaged include IBD, gastroenteritis and coeliac disease.

The symptoms of lactose intolerance include bloating, flatulence, cramping abdominal pain and diarrhoea. They may occur within a half hour to several hours after drinking a glass of milk or ingesting a milk product. The diarrhoea of lactose intolerance results from fluid secretion into the small intestines, responding to the osmotic action of undigested lactose.

Many lactose-intolerant persons are aware of their milk intolerance and avoid milk and milk products. Lactose intolerance can be diagnosed by a lactose tolerance test or a lactose hydrogen breath test.⁵⁵

Treatment consists of eliminating lactose from the diet by avoiding milk and milk products and/or replacement of lactase with commercially available preparations. Milk and ice-cream have much higher lactose content than cheese. Live culture yoghurt is an alternative source of calcium, but the patient needs to be sure that milk products have not been added to the yoghurt. A lactose-free diet is given initially and may be gradually advanced to a low-lactose diet as tolerated by the patient. The objective of care is to teach the importance of adherence to the diet. Many lactose-intolerant persons may not exhibit symptoms if lactose is taken in small amounts. In some persons, lactose may be tolerated better if taken with meals. Since avoidance of milk and milk products can lead to calcium deficiency, supplements may be necessary to prevent osteoporosis. Lactase enzyme is available commercially as an over-the-counter product. It is mixed with milk and breaks down the lactose before the milk is ingested. Soymilk is lactose-free.

Short-bowel syndrome

Short-bowel syndrome (SBS) results from surgical resection, congenital defect or disease-related loss of absorption. It is characterised by a failure to maintain protein–energy, fluid, electrolyte and micronutrient balances on a standard diet. Resection of the small intestine may have been necessary for bowel infarction because of vascular thrombosis or insufficiency, abdominal trauma, cancer, radiation enteritis or Crohn’s disease.

The length and portions of small bowel resected are associated with the number and severity of symptoms. Resections of up to 50% of the small intestine cause little disturbance of bowel function, especially if the terminal ileum and ileocaecal valve remain intact. After large resections, the remaining intestine undergoes adaptive changes that are more pronounced in the ileum. The villi and crypts increase in size, and the absorptive capacity of the remaining intestine increases. Intestinal adaptation is enhanced by the presence of food, fibre, bile and pancreatic secretions in the lumen and continues for up to 2 years. Resection of the ileum, ileocaecal valve or colon results in a rapid intestinal transit and decreased absorption time. Ileal resection causes malabsorption of vitamin B₁₂, bile salts and fat. This results in steatorrhoea.

CLINICAL MANIFESTATIONS

The predominant manifestations of SBS are diarrhoea or steatorrhoea. There may be signs of malnutrition and multiple vitamin and mineral deficiencies (e.g. weight loss, vitamin B₁₂ and zinc deficiency, hypocalcaemia). The patient may develop lactase deficiency and bacterial overgrowth. Oxalate kidney stones may form from increased colonic absorption of oxalate.

MULTIDISCIPLINARY CARE

The overall goals are that the patient with SBS will have fluid and electrolyte balance, normal nutritional status and control of diarrhoea. In the period immediately following massive bowel resection, patients receive parenteral nutrition to replace fluid, electrolyte and nutrient losses to rest the bowel. Proton pump inhibitors are used to decrease gastric acid secretion.

A diet high in carbohydrate and low in fat supplemented with soluble fibre, pectin, the amino acid glutamine and parenteral growth hormone is often recommended. The patient with SBS is encouraged to eat at least six meals a day to increase the time of contact between food and the intestine. Oral intake can be supplemented with elemental nutrient formulas and tube feeding during the night. For patients with severe malabsorption, parenteral nutrition (see Ch 39) may be reinstituted. Oral supplements of calcium, zinc and multivitamins are typically recommended.

Opioid antidiarrhoeal drugs are the most effective in decreasing intestinal motility (see Table 42-2). For patients with limited ileal resections (<100 cm), cholestyramine reduces diarrhoea as a result of unabsorbed bile acids and increases their excretion in faeces. Bile acids stimulate intestinal fluid secretion and reduce colonic fluid absorption.

Gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GISTs) are uncommon connective tissue tumours in the GI tract. Over half occur in the stomach and the upper small intestine. They are less likely to occur in the oesophagus, colon and rectum. There are no known risk factors. However, a familial tendency is present in a small number of patients.⁵⁶

The manifestations of GIST depend on the part of the GI tract affected. Early signs and symptoms are often subtle, including early satiety and bloating. Later manifestations may include GI bleeding and obstruction due to growth of the tumour. Often GIST is found during evaluation (e.g. endoscopy, X-ray) for other problems, such as colorectal or stomach cancer. The diagnosis of GIST is based on histological examination of biopsied tissue. Endoscopic ultrasound can be used to determine the extent of the tumour.

The main treatment of GIST is surgery. However, GIST has often metastasised at the time of diagnosis. Targeted drug therapies include imatinib. Imatinib is not curative and the cancer often returns within 2–5 years.⁵⁶ (Targeted drug therapies are discussed in Ch 15.)

ANORECTAL PROBLEMS

Haemorrhoids

Haemorrhoids are dilated haemorrhoidal veins. They may be internal (occurring above the internal sphincter) or external (occurring outside the external sphincter; see Figs 42-18 and 42-19). Symptoms of haemorrhoids include rectal bleeding, pruritus, prolapse and pain. In affected persons, haemorrhoids appear periodically, depending on the amount of anorectal pressure.

Figure 42-18 Anatomical structures of the rectum and anus with external and internal haemorrhoids.

Figure 42-19 Thrombosed external haemorrhoids.

AETIOLOGY AND PATHOPHYSIOLOGY

Haemorrhoids are thought to develop as a result of shearing forces during defecation. This force damages the supporting muscles. When supporting tissues in the anal canal weaken, usually as a result of straining at defecation, the venules become dilated. In addition, blood flow through the veins of the haemorrhoidal plexus is impaired. An intravascular clot in the venule results in a thrombosed external haemorrhoid. Haemorrhoids are the most common reason for bleeding with defecation. The amount of blood lost at one time may be small but over time may lead to iron-deficiency anaemia. Haemorrhoids may be precipitated by many factors, including pregnancy, prolonged constipation, straining in an effort to defecate, heavy lifting and prolonged standing and sitting.

CLINICAL MANIFESTATIONS

The classic symptoms of haemorrhoidal disease include bleeding, anal pruritus, prolapse and pain. The patient with internal haemorrhoids may be asymptomatic. However, when internal haemorrhoids become constricted, the patient will report pain. Internal haemorrhoids can bleed, resulting in blood on toilet paper after defecation or blood on the outside of stool. The patient may report a chronic, dull aching discomfort, particularly when the haemorrhoids have prolapsed.

External haemorrhoids are reddish blue and seldom bleed or cause pain unless a vein ruptures. Blood clots in external haemorrhoids cause pain and inflammation and the haemorrhoids are described as thrombosed. External haemorrhoids cause intermittent pain, pain on palpation, itching and burning. Patients also report bleeding associated with defecation. Constipation or diarrhoea can aggravate these symptoms.

DIAGNOSTIC STUDIES AND MULTIDISCIPLINARY CARE

Internal haemorrhoids are diagnosed by digital examination, anoscopy and sigmoidoscopy. External haemorrhoids can be diagnosed by visual inspection and digital examination. Therapy is directed towards the causes and the patient’s symptoms. A high-fibre diet and increased fluid intake prevent constipation and reduce straining, which allows engorgement of the veins to subside. The resulting stool bulk may also decrease stool leakage and therefore itching. Ointments, creams, suppositories and impregnated pads that contain anti-inflammatory agents (e.g. hydrocortisone) or astringents (e.g. witch hazel), and anaesthetics (e.g. benzocaine) may be used to shrink the mucous membranes and relieve discomfort. The use of topical corticosteroids such as hydrocortisone agents should be limited to prevent side effects such as contact dermatitis and mucosal atrophy. Stool softeners may be ordered to keep the stools soft. Sitz baths help relieve pain.

External haemorrhoids are usually managed by conservative therapy unless they become thrombosed. Internal haemorrhoids are frequently treated by the non-surgical method of rubber band ligation. An anoscope is inserted so the haemorrhoid can be identified and then ligated with a rubber band. The rubber band around the haemorrhoid constricts circulation, and the tissue becomes necrotic, separates and sloughs off. There is some local discomfort with this procedure but no anaesthetic is required. Oral pain relief may be ordered and sometimes oral metronidazole is given.

A haemorrhoidectomy is the surgical excision of haemorrhoids. Surgery is indicated when there is prolapse, excessive pain or bleeding, or the haemorrhoids are large. In general, haemorrhoidectomy is reserved for patients with severe symptoms related to multiple thrombosed haemorrhoids or marked protrusion. Surgical removal may be done by cautery, clamp or excision. One surgical approach is to leave the area open so that healing takes place by secondary intention. In another approach the haemorrhoids are removed, the tissue is sutured and wound healing takes place by primary intention.

NURSING MANAGEMENT: HAEMORRHOIDS

Conservative nursing management for the patient with haemorrhoids includes teaching measures to prevent constipation, avoidance of prolonged standing or sitting, proper use of over-the-counter drugs available for haemorrhoidal symptoms and the need to seek medical care for severe symptoms of haemorrhoids (e.g. excessive pain and bleeding, prolapsed haemorrhoids) when necessary. Sitz baths (15–20 minutes, two to three times each day for 7–10 days) may be helpful to reduce the discomfort and swelling associated with haemorrhoids.

Pain caused by sphincter spasm is a common problem after a haemorrhoidectomy. The nurse must be aware that although the procedure is minor, the pain is severe. Opioids are usually given initially. Postoperatively, topical glyceryl trinitrate preparations may be used to decrease pain and subsequent opioid use.

Sitz baths are started 1–2 days after surgery. A warm sitz bath provides comfort and keeps the anal area clean. A sponge ring in the sitz bath helps relieve pressure on the area. Initially the patient should not be left alone in the bath because of the possibility of weakness or fainting.

Packing may be inserted into the rectum to absorb drainage. A T-binder may hold the dressing in place. If packing is inserted, it is usually removed on the first or second postoperative day. Pain medication is given prior to this procedure. The nurse should assess for rectal bleeding. The patient may be embarrassed when the dressing is changed, and privacy should be provided. The patient usually dreads the first bowel movement and often resists the urge to defecate. Pain medication may be given before the bowel movement to reduce discomfort.

A stool softener such as docusate is usually ordered for the first few postoperative days. If the patient does not have a bowel movement within 2–3 days, an oil-retention enema is given. Patients are taught the importance of diet, care of the anal area, symptoms of complications (especially bleeding), and avoidance of constipation and straining. Sitz baths are recommended for 1–2 weeks. The healthcare provider may order a stool softener to be taken for a time. Haemorrhoids may recur. Occasionally, anal strictures develop and dilation is necessary. Regular check-ups are important in the prevention of any further problems.

Anal fissure

An anal fissure is a skin ulcer or a crack in the lining of the anal wall that is caused by trauma, local infection or inflammation. Fissures are considered either primary or secondary based on their aetiology. Primary fissures usually occur as a result of local trauma associated with defecation or forced trauma such as rape. When there is high pressure in the internal anal sphincter, it can result in ischaemia, which can lead to fissuring. Thus, conditions that promote constipation are likely to be associated with fissure development. Secondary fissures are due to a variety of conditions, including IBD, prior anal surgery, infection (e.g. syphilis, tuberculosis, Chlamydia, gonorrhoea, herpes simplex virus) and human immunodeficiency virus infection.

The major symptoms are anal pain and bleeding. Pain is especially severe during and after defecation. Bleeding is bright red and usually slight. Constipation results because of fear of pain associated with bowel movements.

Anal fissures are diagnosed through physical examination. Conservative care with fibre supplements, adequate fluid intake, sitz baths and topical analgesics is successful in about half of all cases, especially if the situation is acute.⁵⁷ Topical preparations, including glyceryl trinitrate and calcium channel blockers, are used to decrease rectal anal pressure to allow the fissure to heal without sphincter damage. Local injections of botulin toxin have also been effective in some cases. Pain may be decreased with the use of stool softeners. Warm sitz baths (15–20 minutes, three times a day) and anal anaesthetic suppositories are also ordered.

A lateral internal sphincterotomy is the recommended surgical procedure when conservative treatment fails. Surgical treatment involves excision of the fissure. Problems with incontinence occur in a small number of patients following this procedure. Postoperative nursing care is the same as the care for the patient who has had a haemorrhoidectomy.

Anorectal abscess

Anorectal abscesses are collections of perianal pus (see Fig 42-20). They are the result of obstruction of the anal glands, leading to infection and subsequent abscess formation. Abscess formation can occur secondary to anal fissures, trauma or IBD. The most common causative organisms are Escherichia coli, staphylococci and streptococci. Clinical manifestations include local pain and swelling, foul-smelling drainage, tenderness and elevated temperature. Sepsis can occur as a complication. Anorectal abscesses are diagnosed by rectal examination.