abdomen The area between the chest and the hips that contains the stomach, small intestine, large intestine, liver, gallbladder, pancreas, and spleen.
acid reflux The movement of caustic gastric acid from the stomach into the esophagus.
acupuncture The insertion of needles into various parts of the body, at very specific sites, to cause healing or a change in sensation in other parts of the body.
acute A term used to describe a disorder, disease, or process that is sudden in onset and often severe but lasts only a short time.
aerophagia The abnormal swallowing or gulping of air.
allodynia The misinterpretation of normal sensation as being painful.
allopathic medicine A therapeutic type of medicine in which a specific disease or disorder is treated by producing a second condition that is antagonistic or incompatible with the first condition. Common examples include giving antibiotics to treat a bacterial infection or treating high blood pressure with a medicine designed to reduce blood pressure. Essentially all Western-trained physicians are allopathic physicians.
amylase A digestive enzyme that breaks down starch.
anemia A low blood count as measured by hemoglobin or hematocrit.
anismus Dyscoordination of the muscles in the pelvic floor. Also called pelvic floor dyssynergia. The term anismus is rarely used now; pelvic floor dyssynergia is the preferred term.
anorectal manometry (ARM) A test to evaluate neuromuscular function of the anorectum and the pelvic floor muscles.
antibiotic A type of medication that acts to kill bacteria in the body.
anticholinergic agents Medications that block the effects of acetylcholine, one of the major neurotransmitters in the GI tract.
antispasmodic agents A class of medications that help relax the smooth muscle of the GI tract and thus help prevent spasms in the GI tract.
anxiety A prevalent condition in the U.S., affecting up to 5 percent of the population. Characterized by excessive worry, restlessness, inability to concentrate, poor sleep, irritability, and feeling “keyed up” or “on edge.”
aromatherapy A form of alternative medicine that uses a variety of herbs, oils, and fragrances to promote healing, relaxation, and stress reduction.
arthralgia Pain or discomfort in a joint. This is different from arthritis, which is an inflammatory condition of a joint.
autoimmune disease Any number of processes or conditions where the body’s immune system mistakenly believes that a normal part of the body is “foreign” and starts to attack it, creating inflammation.
autonomic nervous system (ANS) The portion of the nervous system that allows various parts of the body, for example, your heart rate and blood pressure, to function on their own without conscious thought. The ANS can be divided into the sympathetic nervous system and the parasympathetic nervous system.
bacterial overgrowth (also called small intestine bacterial overgrowth, or SIBO). A condition in which an inappropriately large number of bacteria reside in the small intestine. This condition can lead to bloating and diarrhea and may lead to nutritional deficiencies in mild cases or malnutrition in severe cases.
barium A radio-opaque substance used to coat the inside of a hollow organ, such as the esophagus or stomach, so that it can be visualized on an x-ray. A radio-opaque substance is one that x-rays do not penetrate well, so it shows up on an x-ray as a white area.
barium enema An x-ray test in which barium (see above) is inserted into the rectum and then coats the colon so that abnormalities in the colon can be identified.
biofeedback A training technique that teaches patients how to gain control over autonomic (that is, self-regulating) functions of the body. In gastroenterology, biofeedback is often used to treat patients who have pelvic floor dysfunction.
biopsy The technique whereby a small piece of tissue is removed from an organ or structure so that it can be examined with a microscope. During a colonoscopy, a biopsy of your colon or rectum may be taken.
bloating The sensation of gassiness.
borborygmi Rumbling or gurgling noises from the GI tract produced by peristalsis and movement of fluid and gas.
brain-gut axis The bidirectional nerve pathway that connects the brain to the gut.
breath test (also called a breath hydrogen test). A test that measures the excretion (elimination) of hydrogen from the GI tract. Used to diagnose patients who have lactose intolerance, fructose intolerance, or bacterial overgrowth.
celiac disease A wheat allergy. Patients may have mild symptoms of bloating or more severe symptoms of unintentional weight loss, iron deficiency anemia, diarrhea, and/or osteoporosis. Celiac disease is treated by eliminating all wheat products from the diet.
central nervous system (CNS) Consists of the brain and the spinal cord.
chromosome One of the threadlike structures in the cell nucleus that transmits genetic information. Each chromosome consists of a double strand of DNA (see DNA entry) along with proteins called histones. The nucleus of each human cell usually contains 46 chromosomes.
chronic A term used to identify a disorder, disease, or process that continues for a long time or recurs frequently.
chronic fatigue syndrome (CFS) A condition characterized by severe fatigue, lack of energy, and decreased exercise endurance that is not relieved by rest. The cause of CFS is unknown.
chyme The semifluid mass of partly digested food that passes from the stomach into the small intestine.
coccyx The last three to five vertebrae in the vertebral column. These are rudimentary (vestigial) in nature. Commonly referred to as the tailbone.
cognitive behavioral therapy (CBT) A type of psychological therapy where patients learn to address their problem in a proactive, positive manner. Stress reduction and relaxation techniques are often taught as well.
colitis A nonspecific term that indicates the presence of inflammation in the colon. This is not an appropriate term for patients who have IBS, since the colon is not inflamed. This word is best reserved for patients who have true inflammatory bowel disease, that is, Crohn’s disease or ulcerative colitis.
colonoscopy The technique of using a flexible lighted tube to visualize the colon.
complementary and alternative medicine (CAM) A diverse group of treatments and therapies that complement or provide alternatives to traditional Western medicine. This includes hypnotherapy, acupuncture, herbal medicine, etc.
conscious sedation The technique of using intravenous medications to make a patient feel comfortable and relaxed during a procedure, such as a colonoscopy, but not to induce sleep.
constipation A common condition affecting 15 percent of adult Americans. Defined in a number of different ways, including infrequent bowel movements (fewer than three per week), excessive straining at stool, feelings of incomplete evacuation, or pain with defecation.
Crohn’s disease A type of inflammatory bowel disease. In contrast to people who have IBS, patients who have Crohn’s disease have an inflammatory process in their GI tract. This may occur anywhere from the mouth to the anus.
CT scan CT is an abbreviation for computed tomography, a special type of x-ray test that can visualize the internal organs.
cystoscopy A procedure where the interior of the bladder is visualized using a special lighted instrument (a cystoscope).
defecation The act of having a bowel movement.
depression A mental state characterized by feeling sad or blue, often accompanied by feelings of despair, loneliness, or worthlessness. Approximately 5 percent of U.S. adults meet clinical criteria for depression.
diaphragm The muscle between the chest and the abdomen. It is the major muscle that the body uses for breathing.
diarrhea Defined in a number of different ways, but typically characterized by frequent stools (more than three per day) that are loose and watery.
digestion The process the body uses to break down food into simple substances that can be absorbed into the body and used for energy, growth, and cell repair.
digestive system The organs in the body that break down and absorb food. Organs that make up the digestive tract (gastrointestinal tract) are the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Organs that help with digestion but are not part of the digestive tract are the tongue, salivary glands, pancreas, liver, and gallbladder.
distention The physical state of being stretched or swollen.
dizygotic twins (di means “two”) Twins derived from two separate fertilized embryos, in contrast to twins that develop from a single fertilized egg that divides into identical parts (monozygotic twins).
DNA (deoxyribonucleic acid) The material found in the nuclei of cells that makes up the chromosomes and contains the genetic material.
duodenum The first part of the small intestine. It is connected to the stomach by a circular muscle called the pylorus.
dyspareunia Pain with intercourse.
dyspepsia A condition that affects up to 20 percent of adults at some point in their lifetime. Characterized by meal-associated upper abdominal discomfort or pain; may be associated with nausea and a feeling of fullness or being “overstuffed.” This condition frequently overlaps with IBS.
dysphagia Difficulty swallowing. This may occur because of severe heartburn, the presence of a stricture (narrowing) of the esophagus, or even cancer of the esophagus.
efficacy The extent to which an intervention (that is, medication, a procedure, a device, or surgery) produces a beneficial result.
elimination diet A diet used by some health care providers to determine whether a patient has food allergies or food sensitivities. The diet begins with eating only simple foods that rarely cause symptoms in anyone (for example, water, broth, white rice, and boiled chicken), and then different foods are slowly added back to the diet as the patient monitors symptoms.
empiric therapy The practice of using a combination of symptoms and signs to make a diagnosis and then initiating treatment for the presumed problem, without any objective tests being performed.
endoscope A flexible, lighted tube with a lens on the end. It is designed to look into your stomach and esophagus (upper endoscopy) or your colon (colonoscopy).
endoscopy A procedure that uses an endoscope to diagnose or treat a condition within the intestinal tract.
enteric nervous system (ENS) The part of the nervous system within the GI tract that controls gut function.
eructation The medical term for belching or burping.
esophagogastroduodenoscopy (EGD) A procedure that uses an endoscope to look into the esophagus, stomach, and upper small intestine (duodenum). Also called upper endoscopy.
esophagus The muscular tube that connects the mouth to the stomach. Approximately 10 inches long.
etiology The cause of a disease or disorder.
fecal incontinence The unintentional leakage of stool.
fecal urgency The sudden and intense urge to have a bowel movement. Common in patients who have IBS and diarrhea.
fibroymyalgia A syndrome of fatigue and pain in the muscles and fibrous connective tissues. The cause is unknown.
flatulence The presence of an excessive amount of gas in the lower gastrointestinal tract.
flatus The passage of gas from the lower intestinal tract.
flexible sigmoidoscopy A flexible lighted tube designed to visualize the lower colon (descending and sigmoid colon) and rectum.
fructose A simple (single) sugar (a monosaccharide) found in many fruits.
fructose intolerance The clinical condition in which a person cannot adequately digest fructose. This may lead to gas, bloating, and diarrhea.
functional bowel disorders A group of common, chronic conditions (IBS, dyspepsia, aerophagia) that affect the gastrointestinal tract. These disorders cannot be explained by an organic lesion (that is, an ulcer), by a blood disorder (for example, anemia), or by an x-ray test such as a CT scan. The name is appropriate, since patients develop symptoms because their intestinal tract does not function normally.
fundus The uppermost part of the stomach.
gas In clinical practice and for the lay public, gas usually refers to either the feeling of being bloated or distended (“gassiness”) or to the passage of gas from the intestinal tract.
gastric Related to the stomach.
gastrocolic reflex The reflex between the stomach and the colon. Normally, ingesting food or liquid stimulates the stomach, which then initiates a reflex in the colon, leading to contractions and peristalsis. In many patients, this is commonly interpreted as an urge to have a bowel movement. Patients who have IBS often have a heightened or exaggerated gastrocolic reflex, which explains the sense of urgency they develop after eating a meal.
gastroenterologist A doctor who specializes in diagnosing and treating diseases of the digestive system.
gastroenterology The study of the digestive tract and its associated organs, including the liver, pancreas, and gallbladder.
gastroesophageal reflux disease (GERD) The movement of caustic gastric juices from the stomach back up into the esophagus. This movement may occur because of transient relaxation of the lower esophageal sphincter, the presence of a weak lower esophageal sphincter, or poor motility in the body of the esophagus. Prolonged episodes of reflux may cause esophagitis, esophageal ulcers or erosions, strictures, Barrett’s esophagus, or even cancer of the esophagus. GERD is also called esophageal reflux or heartburn.
gastrointestinal tract (GI tract) The large, muscular tube that extends from the mouth to the anus. It includes the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Also called the alimentary tract or digestive tract.
heartburn A burning sensation caused by stomach acid after it moves into the lower esophagus and irritates the lining of the esophagus. It is usually felt in the upper abdomen, in the lower chest, or behind the breastbone (the sternum).
Helicobacter pylori (H. pylori) Bacteria commonly found in the stomach that can cause ulcers and are associated with an increased risk of developing stomach cancer; not related to IBS symptoms.
herbal medicine The practice of using herbs to treat various medical conditions and diseases.
homeopathy A system of therapy which is based on the belief that a substance that can provoke certain symptoms or induce an illness in a patient may be effective at treating different illnesses that have similar symptoms.
hypnosis An artificially induced trance or a period of deep concentration in which certain states of awareness are temporarily suspended. Used by some practitioners to treat patients who have functional bowel disorders by providing them with advice and suggestions during a period of increased susceptibility.
hypnotherapy The practice of using hypnosis to treat a variety of medical conditions.
ileum The third portion of the small intestine; follows the duodenum (the first part) and the jejunum (the second part).
incidence The number of new cases or events that occur during a specified time period.
incomplete evacuation The sensation some people have after a bowel movement, in contrast to the feeling some people have after a complete or “full” evacuation.
incontinence The accidental leakage of material from the bladder (urinary incontinence) or rectum (fecal incontinence).
inflammatory bowel disease One of two separate conditions, either Crohn’s disease or ulcerative colitis. Both of these disorders typically cause diarrhea and abdominal pain. However, both of these conditions are characterized by inflammation in the GI tract and thus are completely distinct disorders from IBS.
inflammatory colitis An outdated term used many years ago to describe IBS. However, since the intestinal tract is not inflamed, inflammatory colitis is an inaccurate term that should not be used to describe people who have IBS.
interstitial cystitis A condition of the bladder characterized by pain, urinary urgency, and urinary frequency. Often seen with people who have IBS.
ischemic colitis An inflammatory condition of the colon that develops due to inadequate blood flow (ischemia).
jejunum The second portion of the small intestine (after the duodenum).
lactose A disaccharide, made up of the simple sugars glucose and galactose. Lactose is found in dairy products such as milk and cheese.
lactose intolerance The clinical condition in which a patient is unable to break down the sugar commonly found in milk products. This may lead to gas, bloating, and diarrhea.
lower esophageal sphincter (LES) A circular muscle, approximately 1½ inches in length, located at the junction of the esophagus and the stomach. When contracted, it prevents stomach acid from refluxing up into the esophagus. If it relaxes too frequently, or for prolonged periods of time, then gastric acid can easily rush up into the esophagus and cause heartburn.
manipulation therapy The process of using massage to promote healing and release of blocked energy. Examples include Rolfing, shiatsu, and reflexology.
Manning criteria A set of criteria used to diagnose IBS. No longer used in research studies or clinical practice since the advent of the Rome criteria.
microflora or microbiota The normal population of bacteria that resides in the intestinal tract (primarily the large intestine).
migraine headache A type of headache characterized by pain in the head (usually only on one side), nausea, vomiting, and light sensitivity. Some patients also notice “flashing” lights and peculiar smells (burnt rubber, eggs).
monozygotic twins Also called identical twins. Twins that develop from a single fertilized egg, which then divides into identical parts that develop into individuals with the same sex and the same genetic components.
motility The normal process, coordinated by nerves and smooth muscle, that results in coordinated contractions in the digestive tract. Motility results in the normal movement of food and liquids through the upper GI tract and liquid and solid waste through the lower GI tract.
mucus A clear liquid made by cells that line the intestinal tract. Mucus coats and protects tissues in the gastrointestinal tract.
mucus colitis An outdated term for IBS. Used in the past because some patients note that they pass mucus during or after a bowel movement. This term is inaccurate and should be discarded.
myalgia Muscle ache or discomfort.
natural history The normal and natural course of a disease or disorder over time if treatment is not provided.
naturopathy The practice of healing using only natural agents (that is, no drugs).
nervous colitis An outdated term for IBS that should be discarded.
panic disorder A disorder characterized by extreme anxiety, agitation, fear, and often feelings of dread. Patients may also experience sweating, difficulty breathing, and an increased heart rate.
parasympathetic nervous system One of the two major divisions of the autonomic nervous system (the other being the sympathetic nervous system). In general, the parasympathetic nervous system leads to a quieting of body functions (for example, decreased heart rate), although it plays a major role in stimulating peristalsis in the GI tract.
pathophysiology The alteration or abnormality of function seen with a medical disease or condition.
pelvic floor The group of muscles (puborectalis, pubococcygeus, and iliococcygeus) that support the internal organs in the pelvis (bladder, urethra, rectum, vagina, cervix, uterus, prostate gland, and anal canal).
pelvic floor dyssynergia A condition that may cause constipation. Characterized by inappropriate contraction of the external anal sphincter muscle during attempted defecation or inability to relax the internal anal sphincter.
pelvis The cup-shaped ring of bone formed by the hip bones (pubic bone, ischium, and ilium) on both sides and in front and the sacrum and coccyx behind.
perforation A hole that develops in a hollow organ such as the colon, stomach, or esophagus. A perforation may develop due to an ulcer in the stomach or may result from a foreign object in the GI tract or trauma to the GI tract (a sharp object, accidentally swallowing a sharp bone, endoscopy).
peripheral nervous system This consists of the autonomic nervous system (ANS) and the somatic nervous system.
peristalsis The muscular contractions of the gastrointestinal tract that move materials from the esophagus to the rectum.
pharynx The space behind the mouth. It serves as a passageway for food from the mouth to the esophagus and for air from the nose and mouth to the larynx and then into the lungs.
physiology A general term that refers to the normal functioning and vital processes of an entire organism (for example, a person) or a specific organ (for instance, the liver).
placebo A mostly inert substance (a pill with no intentionally active ingredients) that can be given as a medicine due to its suggestive effects. Commonly used in research trials to allow a better understanding of the true effects of the medicine being tested.
positron emission tomography (PET) scan A special type of radiologic test that can detect changes in the activity or metabolism of a cell. This test requires the injection of a radioactive material called a tracer. It is most frequently used to help detect cancer.
postprandial The period of time after eating a meal.
prevalence The number of cases of a disease (or disorder) that exist in a population at a specific time.
probiotic A live microbial organism (bacteria) introduced to promote health in the GI tract.
prognosis The long-term outcomes of a disease, either with or without treatment.
prokinetic agents A class of medications that act on the gastrointestinal tract to increase contractions and peristalsis in the GI tract. These agents may help to empty the stomach or to increase peristalsis in the small or large intestine.
prolapse When an organ sinks down out of the normal position. Most commonly refers to prolapse of the uterus (when it moves lower in the pelvic cavity), the bladder, or the rectum. Excessive prolapse of any of these organs usually requires surgery.
pylorus The circular muscle at the junction of the stomach and the duodenum. When contracted (closed), it prevents gastric contents from leaving the stomach and entering the duodenum.
quality of life A global term used to measure satisfaction and happiness with our daily lives and all of the daily activities we try to perform. An important concept in IBS research studies, because it allows patients to describe how a specific illness or disorder affects them.
Rome criteria The most recent and accurate set of diagnostic characteristics for irritable bowel syndrome, including symptoms, duration, and frequency.
scybala Hard, rocky, pellet-like stools (singular scybalum).
serotonin One of the most important neurotransmitters in the GI tract. Serotonin (also called 5-hydroxytryptamine) plays a critical role in both normal and abnormal gut function.
sign What a physician finds on physical examination (in contrast to a symptom—see below).
sitz marker study An x-ray study that measures transit of materials through the colon. Patients swallow a gelatin capsule that contains radio-opaque markers. X-rays of the abdomen are then performed at specific times to measure the movement of the markers through the colon. Typically performed in patients with constipation who have not responded to standard therapies.
smooth muscle One of the three types of muscle in the body, the others being cardiac (heart) muscle and skeletal muscle. Smooth muscle lines the entire GI tract, from the upper esophagus to the anorectum.
SNRIs (serotonin norepinephrine reuptake inhibitors) A class of medications used to treat depression.
somatic Refers to the muscles, bones, and joints in the body.
somatic nervous system (also called the voluntary nervous system). This system is responsible for transmitting information from the brain to skeletal muscle.
somatization disorder An uncommon disorder in which psychological or psychiatric problems (for example, anxiety or depression) are translated into physical problems. Patients who have a somatization disorder suffer from multiple, recurrent physical complaints and symptoms without an underlying organic cause. Many patients who have somatization disorders believe that all of their body is sick and dysfunctional.
sorbitol A sugar that is poorly broken down in the upper GI tract in some people. If large amounts are ingested, then bloating, gas, cramps, and diarrhea may ensue.
spastic colitis An old, outdated term for IBS. Factually incorrect, because the colon is not inflamed in IBS.
SSRIs (selective serotonin reuptake inhibitors) The class of medications most commonly used to treat depression.
stomach The J-shaped muscular organ designed to hold food, mix and grind food, and then empty the ground-up food into the small intestine. The stomach also produces a variety of chemicals, the most important of which is hydrochloric acid. This is the acid responsible for causing heartburn when it refluxes into the lower esophagus.
sympathetic nervous system One of the two major subdivisions of the autonomic nervous system (the other being the parasympathetic nervous system). In general, stimulation of the sympathetic nervous system leads to a state of arousal and heightened sensations throughout the body (for instance, increased heart rate and increased awareness) except in the GI tract, where sympathetic stimulation leads to decreased activity.
symptom A feeling or sensation that a patient may report to a health care provider.
syndrome A collection of symptoms and signs that occur together.
TCAs (tricyclic antidepressants) This class of medications was used to treat depression in the past. However, they were generally not very effective at treating depression. These agents can, however, be very helpful with treating chronic pain, especially the chronic abdominal pain of IBS and dyspepsia.
TMJ syndrome (temporomandibular joint syndrome) A painful condition of the jaw that is often associated with difficulty opening the mouth.
trigger points Also called tender points. These are specific points on the body which, when pressed, cause significant pain or discomfort in patients with fibromyalgia.
ulcer A sore on the lining of the esophagus, stomach, or intestine. Often caused by excess acid, medications, poor blood flow, or the bacterium Helicobacter pylori.
ulcerative colitis A form of inflammatory bowel disease (the other major one being Crohn’s disease). This condition is very different from IBS, because with ulcerative colitis, the colon is inflamed. This can cause chronic bleeding from the colon.
unstable colitis / unstable colon These are older terms used to describe IBS. They should be discarded, since they are factually incorrect (patients who have IBS do not have colitis, which is an inflammatory condition of the colon).
upper endoscopy See esophagogastroduodenoscopy upper esophageal sphincter The circular band of muscle at the top of the esophagus. It is usually contracted and helps to prevent acid from moving from the esophagus into the lungs and mouth.
upper GI series (upper gastrointestinal series) An x-ray study that usually employs barium as the contrast agent. A patient swallows the barium, which coats the esophagus, stomach, and upper small intestine. X-rays are then taken to look for abnormalities, such as ulcers, erosions, strictures, or cancer, in the lining of these organs.
urgency The sudden feeling of needing to use the bathroom immediately, often for fear of having an accident.
video defecography An x-ray test designed to measure function of the anorectum and the pelvic floor. Thick barium paste is inserted into the rectum, and then x-rays are taken as the patient attempts to expel the material.
viscera Refers to the internal organs (colon, small intestine, stomach, etc.).
Viscus is the singular form.
visceral hypersensitivity This refers to the finding that patients who have IBS have a lower threshold for sensing pain in their GI tract.
zygote A fertilized egg. The cell that develops from the union of an egg with a sperm.