DIVERTICULAR DISEASE

Jin Sol Oh, MD • David Hardy, MD, RPVI • Steven B. Holsten Jr., MD, FACS

 BASICS

DESCRIPTION

Diverticulum (single) or diverticula (multiple) are outpouchings in the colonic wall. Diverticular disease is a spectrum of diseases occurring with diverticulosis.

•  Asymptomatic diverticulosis: common incidental finding on routine colonoscopy. Symptomatic diverticulosis: also known as symptomatic uncomplicated diverticular disease. Recurrent abdominal pain attributed to diverticulosis without colitis or diverticulitis (1)

•  Acute diverticulitis: diverticular inflammation and/or infection

–  Uncomplicated diverticulitis: left lower quadrant (LLQ) pain, tenderness, leukocytosis, but no peritoneal signs or systemic toxicity

–  Complicated diverticulitis: secondary abscess formation, bowel obstruction or perforation, peritonitis, fistula, or stricture.

•  Diverticular bleeding

–  Accounts for >40% of lower GI bleeds and 30% of cases of hematochezia in general

–  Bleeding more common with right-sided diverticula

•  System affected: entire GI tract except the rectum

EPIDEMIOLOGY

Incidence

•  Diverticular disease accounts for ~300,000 hospitalizations per year in the United States.

•  Diverticulitis occurs in 1–2% of the general population and in 4% of patients with diverticulosis over the course of their lifetime (1).

•  Diverticular bleeding occurs in 3–5% of patients with diverticulosis.

Prevalence

•  Prevalence of diverticulosis and the number of diverticula increase with age

–  Diverticulosis occurs in 60% of the population above the age of 60 years and 70% by age of 80 years.

–  Increased from 62 to 75/100,000 persons from 1998 to 2005; large increase in incidence for patients <45 years of age, due to changes in diet

•  Male = female overall. More common in men <65 years of age and more common in women >65 years

ETIOLOGY AND PATHOPHYSIOLOGY

A diverticulum forms where intestinal blood flow (vasa recta) penetrates the colonic mucosa. This results in decreased resistance to intraluminal pressure.

•  Age-related degeneration of mucosal wall, increased intraluminal pressure from dense, fiber-depleted stools, and abnormal colonic motility contribute to diverticulosis.

•  Most right-sided diverticula are true diverticula (all layers of the colonic wall).

•  Most left-sided diverticula are pseudodiverticula (outpouchings of the mucosa and submucosa only).

•  Diverticulitis occurs when local inflammation and infection contribute to tissue necrosis with risk for mucosal micro- or macroperforation.

•  Diverticulitis: microscopic examination reveals inflammation with lymphocytic infiltrate, ulceration, mucin depletion, necrosis, Paneth cell metaplasia, and cryptitis

•  Alterations in intestinal microbiota contribute to chronic inflammation (1,2).

•  Thinning of the vasa recta over the neck of the diverticula increases susceptibility to bleeding.

•  Diverticular disease and irritable bowel syndrome (IBS) may be on the same disease continuum.

Genetics

•  No known genetic pattern

•  Asian and African populations have lower overall prevalence but develop diverticular disease with adoption of a Western lifestyle.

RISK FACTORS

•  Age >40 years

•  Low-fiber diet

•  Sedentary lifestyle, obesity

•  Previous diverticulitis. Risk rises with the number of diverticula.

•  Smoking increases the risk of perforation (1).

•  Diverticular bleeding: increased risk with NSAIDs, steroids, and opiate analgesics. Calcium channel blockers and statins appear to be protective against diverticular bleeding.

GENERAL PREVENTION

•  High-fiber diet or nonabsorbable fiber (psyllium)

•  Vigorous physical activity

COMMONLY ASSOCIATED CONDITIONS

Connective tissue diseases, colon cancer, and inflammatory bowel disease

 DIAGNOSIS

HISTORY

•  Diverticulosis

–  80–85% of patients are asymptomatic. Of the 15–20% with symptoms, 1–2% will need hospitalization and 0.5% will need surgery.

–  Abdominal pain is most common symptom: dull, colicky, primarily LLQ. Pain can be exacerbated by eating and by bowel movement or passage of flatus.

–  Diarrhea or constipation

•  Diverticulitis: uncomplicated (85%) and complicated (15%)

–  Abdominal pain: acute onset, typically in LLQ

–  Fever and/or chills

–  Anorexia, nausea (20–62%), or vomiting

–  Constipation (50%) or diarrhea (25–35%)

–  Dysuria and urinary frequency suggest bladder or ureteral irritation.

–  Pneumaturia and fecaluria can occur if colovesical fistula develops.

•  Diverticular bleeding

–  Melena, hematochezia

–  Painless rectal bleeding

•  Immunocompromised patients may not present with fever or leukocytosis but are at higher risk for perforation and abscess formation (2).

PHYSICAL EXAM

•  Diverticulosis

–  Exam may be completely normal.

–  May have intermittent distension or tympany

–  No signs of peritoneal inflammation

–  May have heme + stools

•  Diverticulitis

–  Abdominal tenderness usually localized to the LLQ.

–  Rebound tenderness, involuntary guarding, or rigidity (suggests peritoneal inflammation or potential bowel perforation)

–  Palpable mass in LLQ (20%)

–  Abdominal distension and tympany

–  Bowel sounds hypoactive (could be high-pitched and intermittent if obstruction ensues)

–  Rectal exam may reveal tenderness or mass.

–  Colovaginal, colovesical, and perirectal fistulae may be the initial manifestation (rarely).

DIFFERENTIAL DIAGNOSIS

Urinary tract infection, nephrolithiasis, irritable bowel syndrome, lactose intolerance, carcinoma, inflammatory bowel disease, fecal impaction, bowel obstruction, angiodysplasia, ischemic colitis, acute appendicitis, ectopic pregnancy

DIAGNOSTIC TESTS & INTERPRETATION

Initial Tests (lab,imaging)

•  Asymptomatic diverticulosis: no labs or imaging needed

•  Acute diverticulitis

–  WBC is normal in up to 45% of cases. As diverticulitis worsens, WBC elevated with left shift.

–  Hemoglobin normal (unless bleeding)

–  ESR elevated

–  Urinalysis may show microscopic pyuria or hematuria.

–  Urine culture: usually normal. Persistent infection suspicious for colovesical fistula

–  Blood cultures positive in systemic cases

–  Plain films of the abdomen (acute abdominal series—supine and upright) to assess for air under the diaphragm (bowel perforation) and signs of bowel obstruction (dilated loops of bowel)

–  CT scan with IV, oral, and/or rectal contrast (sensitivity: 98%, specificity: 99%) to stage disease and determine treatment plan (3)[A]

–  Ultrasound and MRI (sensitivity: 94%, specificity: 92%) are useful alternatives.

–  Barium enema is not recommended due to risk of peritoneal extravasation.

•  Diverticular bleeding/hematochezia

–  Decreased hemoglobin with bleeding

–  Obtain coagulation panel for coagulopathy.

Diagnostic Procedures/Other

•  Diverticular bleeding/hematochezia

–  Endoscopy is the test of choice to evaluate GI bleeding (4).

–  Place NG tube for lavage to exclude upper GI bleeding (4).

–  Angiography if bleeding obscures endoscopy or when endoscopy cannot visualize a source (4)

–  99mTc-pertechnetate–labeled RBC scan (more sensitive) with follow-up angiography to localize bleeding (not studied in a comparison trial) (4)

•  Diverticulitis: gallium- or indium-labeled leukocytes to localize abscess (rarely used)

 TREATMENT

GENERAL MEASURES

•  Diverticulosis: Outpatient therapy with fiber supplementation and/or bulking agents (psyllium) is recommended (>30 g/day) (3)[A].

•  Uncomplicated diverticulitis: Outpatient therapy with or without oral antibiotics. 1–2% of subjects require hospitalization for toxicity, septicemia, peritonitis, or failure of symptoms to resolve. Up to 30% of patients may require surgery at first episode of diverticulitis.

•  Complicated diverticulitis: requires hospitalization, bowel rest, and IV antibiotics until symptoms improve. Hinchey classification to describe severity

–  Stage I: diverticulitis + confined paracolic abscess or phlegmon

–  Stage II: diverticulitis + distant abscess

–  Stage III: diverticulitis + purulent peritonitis

–  Stage IV: diverticulitis + fecal peritonitis

•  Symptomatic improvement is expected within 2 to 3 days. Antibiotics should be continued for 7 to 10 days.

•  Diverticular bleeding: 80% of the cases resolve spontaneously (4).

MEDICATION

First Line

•  Symptomatic diverticulosis: cyclical rifaximin 400 mg PO BID for 7 days every month or continuous mesalamine 800 mg PO BID (3)[C]

•  Acute diverticulitis

–  The routine use of antibiotics in uncomplicated diverticulitis is controversial (3,5)[C].

–  Outpatient: PO antibiotics: Cover for anaerobes and gram-negatives with:

  A fluoroquinolone (ciprofloxacin 750 mg BID or levofloxacin 750 QD) plus metronidazole 500 mg TID (may use clindamycin if metronidazole intolerant) or

  Trimethoprim/sulfamethoxazole DS BID plus metronidazole 500 TID

  Treat for 7 to 10 days.

–  Inpatient: Use IV antibiotics.

  Monotherapy with a β-lactam/β-lactamase inhibitor: piperacillin/tazobactam (3,375 g IV QID) or ampicillin/sulbactam 3 g IV q6h or ertapenem (1 g IV QD)

  Penicillin-allergic patient: quinolone (levofloxacin 750 mg IV QD plus metronidazole 500 mg IV TID)

  Unresponsive or severe disease: imipenem or meropenem

–  Recurrences of acute diverticulitis may be decreased by using mesalamine ± rifaximin (7)[A] or probiotics.

•  Diverticular bleeding

–  Consider vasopressin 0.2 to 0.3 units/min through selective intra-arterial catheter.

•  Precautions

–  Avoid morphine and other opiates that may increase intraluminal pressure or promote ileus.

–  Increased fiber intake is not recommended in the acute management of diverticulitis.

Second Line

•  Outpatient: amoxicillin/clavulanate monotherapy (875/125 mg BID) (contraindicated in patients with clearance <30 mL/min) or moxifloxacin (400 mg PO QD) plus metronidazole (500 mg PO TID)

•  Severely ill inpatients: ampicillin (500 mg IV q6h) + metronidazole (500 mg IV TID) + a quinolone or ampicillin + metronidazole + an aminoglycoside

ISSUES FOR REFERRAL

•  After resolution of diverticulitis (typically 6 to 8 weeks), perform colonoscopy to exclude malignancy, fistula, strictures, or inflammatory bowel disease (3).

•  Patients with complicated diverticulitis (hemodynamic instability or failure to respond to initial IV antibiotic therapy) should have appropriate surgical and critical care/infectious disease consultations.

SURGERY/OTHER PROCEDURES

•  Indications for emergent surgery: peritonitis, uncontrolled sepsis, perforated viscus, colonic obstruction, or acute deterioration

•  Elective resection in nonemergent or recurrent cases of diverticulitis is a case-by-case decision (3):

–  After first episode of diverticulitis, there is a 33% chance of recurrence. After a second episode, there is a 66% chance of further recurrence.

–  Most complications occur during first bout of diverticulitis.

–  Emergent surgery carries a much higher risk of morbidity/mortality.

–  Recommendations for elective surgery are based on severity of complications (not solely on number of recurrences).

–  Elective resection is typically advised after recovery from a bout of complicated diverticulitis that is treated nonoperatively (3).

–  Immunocompromised patients are more likely to present with acute complicated diverticulitis, fail medical management, and have complications from elective surgery.

•  Large abscesses (>4 cm) can be drained with radiographic guidance and managed nonoperatively (3).

•  Diverticular bleeding

–  Endoscopy and hemostasis by epinephrine injection, electrocautery, or clipping (4).

–  Angiography can identify bleeding source and embolize the feeding artery (4).

–  Massive or recurrent bleeding requires evaluation for limited or subtotal colonic resection.

COMPLEMENTARY & ALTERNATIVE MEDICINE

Probiotics such as Lactobacillus casei and Escherichia coli Nissle 1917 have been used to prevent recurrence with mixed success.

ADMISSION, INPATIENT, AND NURSING CONSIDERATIONS

•  Admit for toxicity, sepsis, and/or peritonitis.

•  Admit patients who cannot tolerate oral intake or who need IV fluids, analgesics, antibiotics, bowel rest, and NG suction.

 ONGOING CARE

DIET

•  NPO during acute diverticulitis; advance diet as tolerated as bowel function returns

•  Patients with known diverticulosis or a history of diverticulitis should consume a high-fiber diet to prevent recurrence (5).

•  Avoiding nuts and popcorn is not necessary (5).

PROGNOSIS

•  Good with early detection and prompt treatment

•  Risk for recurrence increases with each subsequent bout of diverticulitis.

•  Younger patients are more likely to have recurrence.

•  Rebleeding occurs in up to 6%.

•  Diverticulitis recurs more often in younger patients, but severity is similar to elderly.

COMPLICATIONS

Hemorrhage, perforation, peritonitis, obstruction, abscess, or fistula

REFERENCES

1.  Strate LL, Modi R, Cohen E, et al. Diverticular disease as a chronic illness: evolving epidemiologic and clinical insights. Am J Gastroenterol. 2012;107(10):1486–1493.

2.  Sheth AA, Longo W, Floch MH. Diverticular disease and diverticulitis. Am J Gastroenterol. 2008;103(6):1550–1556.

3.  Feingold D, Steele SR, Lee S, et al. Practice parameters for the treatment of sigmoid diverticulitis. Dis Colon Rectum. 2014;57(3):284–294.

4.  Zuccaro G Jr. Management of the adult patient with acute lower gastrointestinal bleeding. American College of Gastroenterology. Practice Parameters Committee. Am J Gastroenterol. 1998;93(8):1202–1208.

5.  Stollman N, Smalley W, Hirano I. American Gastroenterological Association Institute guideline on the management of acute diverticulitis. Gastroenterology. 2015;149(7):1944–1949.

ADDITIONAL READING

•  Boynton W, Floch M. New strategies for the management of diverticular disease: insights for the clinician. Therap Adv Gastroenterol. 2013;6(3):205–213.

•  Katz LH, Guy DD, Lahat A, et al. Diverticulitis in the young is not more aggressive than in the elderly, but it tends to recur more often: systematic review and meta-analysis. J Gastroenterol Hepatol. 2013;28(8):1274–1281.

•  Templeton AW, Strate LL. Updates in diverticular disease. Curr Gastroenterol Rep. 2013;15(8):339.

 CODES

ICD10

•  K57.90 Dvrtclos of intest, part unsp, w/o perf or abscess w/o bleed

•  K57.30 Dvrtclos of lg int w/o perforation or abscess w/o bleeding

•  K57.92 Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding

CLINICAL PEARLS

•  Diverticular disease is age-related and more prevalent in patients with a sedentary lifestyle who consume a Western diet.

•  Patients with diverticular disease benefit from a high-fiber diet.

•  The decision for surgery in diverticulitis and diverticular bleeding is made on a case-by-case basis.