Irritable Bowel Syndrome (IBS) Glossary

The large cavity between the chest and the pelvis containing the stomach, small intestine, colon (large bowel), liver, gallbladder, and spleen.
Abdominal cramps
Cramps, or spasms with acute pain, in the region of the stomach and bowels.
Abdominal pain
Pain in the region of the stomach and bowels: also known as stomach ache, belly ache, a sore tummy, gut pain, abdominal cramps, and many other terms.
The process in which food nutrients are taken from the intestinal lumen into the bloodstream for distribution to all cells in the body.
A medicine that counteracts or neutralizes acids. usually in the stomach or duodenum.
Antidiarrheal drugs
Drugs that help to control diarrhea.
Antispasmodic drugs
Drugs that lessen the severity of intestinal muscle spasms (cramps).
The lower opening of the digestive tract through which feces (bowel movements) are discharged.
The condition in which antibodies are produced against the body’s own tissues as in autoimmune diseases.
Synonym for germs. As single-cell organisms found almost everywhere, some bacteria help make cheese and wine, some assist in the digestive process, and some cause disease.
The main ingredient of barium sulfate, given by mouth or rectum to patients undergoing one or more of the tests in the barium studies. Barium sulfate outlines the hollow organs of the digestive tract and makes them visible on x-ray images and under the fluoroscope.
Barium enema
Lower gastrointestinal (GI) series. A diagnostic procedure in which x-rays are taken after barium sulfate is introduced into the patient by enema. The barium sulfate helps to outline the colon and rectum so that they appear clearly on the x-rays.
Barium meal
Upper gastrointestinal (Gl) series. A diagnostic procedure in which x-rays are taken after the patient swallows barium sulfate. The barium sulfate helps to outline the esophagus, stomach, and duodenum so that they appear dearly on the x-rays.
A complex fluid, produced by the liver and stored in the gallbladder, that aids in the digestion of fats and is used by the body to dispose of wastes that do not dissolve in water.
Bile acids
Weak acids (formed in the body from cholesterol) that are secreted by the liver and act as detergents aiding in the digestion of fats.
Bile ducts
The system of tubes that carries bile from the liver to the gallbladder and, when needed, to the intestine.
A feeling of fullness in the abdomen, often occurring after meals.
Bristol Stool Form Scale
A seven group classification of the form that appears upon defecation of human feces. (Bristol Stool Form Scale)
A dilated pouch that forms the first part of the large intestine and connects the colon to the ileum.
Celiac sprue (Celiac Disease, gluten intolerance, gluten sensitive enteropathy)
An inherited disorder in which the lining of the small intestine is damaged when the affected individual eats wheat, rye, oats, or barley. Gluten, a protein in these grains, is thought to be the offending agent.
The most abundant sterol in animal issue, also abundant in bile and gallstones.
Of long duration, often years.
Chronic Idiopathic Constipation (CIC)
Chronic Idiopathic Constipation (also known as functional constipation) share many of the same symptoms as IBS-C and is usually treated the same way.
Inflammation of the colon.
The part of the large intestine extending from the cecum to the rectum.
A short/long, rigid/flexible, narrow endoscope passed through the anus to look into the colon.
CT (Computerized tomography) scanning
A diagnostic procedure in which the x-ray source rotates around the patient so that an x-ray beam is sent through the patient from many different angles. The x-rays are read by a computer, which constructs three-dirnensional images of the body. CT is a painless procedure.
Infrequent and/or difficult passage of stools.
Crohn’s disease
A chronic recurring inflammatory disease that can affect any part of the gastrointestinal tract but most often affects the ileum or colon.
Diagnostic imaging
The use of x-ray or ultrasound pictures of the body organs to make diagnoses.
A condition in which bowel movements are passed more often than usual and in a more or less liquid state.
Dietary fiber
The indigestible, nonstarch material – such as hemicellulose, plant gums, pectins, celluloses-found in the cell walls of plants. Dietary fiber is found in a wide variety of plant foods, including whole grain breads and cereals, fresh fruits and vegetables, and nuts. Because dietary fiber resists digestion in the gastrointestinal tract, it accounts for a significant portion of the solid matter in bowel movements.
The process of breaking down food into simpler chemical compounds that are capable of being absorbed by the intestine.
Digestive juices
Acids, enzymes and other chemicals produced by the body to break down the food we eat into nutrients that can be absorbed.
Digestive tract:
The series of organs from the mouth to the anus that have the function of digesting food.
Disorders of the Gut-Brain Interaction (DGBIs)
Formerly known as Functional Gastrointestinal Disorders (FGIDs).
A visible increase in the waistline. Often occurring after meals.
A condition in which diverticula become inflamed.
A condition in which small sacs (diverticula) form in the wall of the colon. This condition is common among elderly people.
A small sac that forms on the wall of a hollow organ (usually the colon). The plural form is diverticula.
The first part of the small intestine.
Another name for indigestion.
Early satiety
Feeling full before completing a normal sized meal.
A small, flexible tube-like instrument, with a light on the end of it and consisting of thousands of tiny glass fibers, that allows a doctor to see into the esophagus, stomach, duodenum, and colon. An endoscope also allows a doctor to perform biopsies, take color photographs, and perform certain medical procedures that would otherwise require surgery.
A procedure in which an endoscope is used.
Inflammation of the small intestine.
A protein that speeds up certain chemical processes. In the intestine, enzymes are needed to break down many foods into simpler substances so that they can be absorbed.
To discharge wastes from the blood or body tissues.
Solid body wastes, passed as bowel movements.
The process by which bacteria break down substances, yielding alcohols, acids, and gases. In the colon, bacteria break down undigested bits of food, releasing hydrogen and carbon dioxide.
The part of a plant that is not digested. Fiber plays a role in controlling the consistency of stool and the speed at which it is moved through the digestive system.
The passage of gas through the rectum, a normal occurrence-but troublesome if the frequency or volume is excessive or if the sound or odor is offensive.
Gas that is passed by the rectum.
A device used to examine the organs of the digestive tract by means of x-rays.
An acronym to classify groups of carbohydrates (sugars and fibers) found in foods and beverages, that are similar in length and structure and shown to be poorly absorbed in individuals living with IBS. FODMAP = F – Fermentable, O – Oligosaccharides, D – Disaccharides, M – Monosaccharides, A – AND, P – Polyols
Functional disorder
A disorder in which there are no visible signs of disease, yet sometimes the intestinal tract does not seem to function properly. Such a disorder can cause discomfort but is not life threatening and never leads to serious disease.
A sac located beneath the liver that stores bile. The gallbladder can store about 1/2 pint of bile, which is emptied through the bile ducts to the duodenum after food is eaten.
Gallstone disease (gallbladder disease)
The condition of having gallstones in the gallbladder or lodged in one of the ducts leading to or from the gallbladder.
Solid masses that form in the gallbladder or bile ducts. Stones are composed largely of scholesterol and bilirubin in varied proportions.
Located in the stomach, as in “gastric ulcer”
Gastric juices
Liquids produced in the stomach to aid digestion and kill bacteria.
Inflammation of the lining of the stomach .
Inflammation of the lining of both the stomach and the intestine.
A doctor who specializes in treating diseases and disorders of the digestive system.
Gastroesophageal Reflux Disease (GERD)
Occurs when stomach contents repeatedly flow backward, or reflux, into the esophagus, causing irritation
A chronic digestive condition characterized by slowly emptying of the stomach which can cause severe life-limiting symptoms throughout the digestive system and beyond.
Visual inspection of the stomach through a long, flexible tube with a light on the end that is swallowed by the patient.
The most common simple sugar found in nature.
A protein in cereal grains. Wheat, rye, barley, and oats contain the gliadin subfraction of gluten that is toxic to persons with celiac sprue.
Dilation of the veins in the anal area. The problems associated with hemorrhoids occur when these veins become enlarged, prolapsed, or become plugged or inflamed.
A term used to describe conditions that are passed genetically from parents to children.
See Inflammatory Bowel Disease.
Having diagnosis of both IBD and IBS.
See Irritable Bowel Syndrome
Irritable Bowel Syndrome alternating between diarrhea and constipation. Also referred to as IBS-M.
Irritable Bowel Syndrome with predominant constipation.
Irritable Bowel Syndrome with predominant diarrhea.
Irritable Bowel Syndrome with mixed habits; constipation and diarrhea. Also referred to as IBS-A.
Post-infectious Irritable Bowel Syndrome; development of IBS symptoms after a gastronintestinal illness, ie: food poison, gastroenteritis, infection.
Unclassified Irritable Bowel Syndrome.
The lowest part or end of the small intestine.
A hardened mass of stool difficult to pass from the body.
A term used to indicate any disruption in the digestive process. Symptoms commonly include heartburn, nausea, bloating, and gas. Doctors often call it dyspepsia.
Infectious diarrhea (traveler’s diarrhea)
A diarrheal illness caused by an infectious agent: bacterial, viral, or protozoan.
A condition in which the body is trying to respond to localized injury or destruction of tissues. All or some of’ these signs are present: redness, heat, swelling pain, and loss of function.
Inflammatory Bowel Disease (IBD)
A name for a group of disorders in which various parts of the intestinal tract are inflamed. The most common disorders are Ulcerative Colitis and Crohn’s disease.
Intestinal flora
The name for the bacteria, yeasts, and fungi that normally grow in the intestinal tract.
Intestinal mucosa (intestinal lining)
The surface lining of the intestines in which the process of absorption occurs.
Irritable Bowel Syndrome (IBS)
One of the Disorders of the Gut-Brain Interaction (DGBIs), formerly known as Functional Gastrointestinal Disorders (FGIDs). Refers to a complex interaction among factors such as a disturbance in the gut bacteria, altered immune function of the gut lining, altered gut signalling (visceral hypersensitivity) and central nervous system dysregulation of the gut signalling and gut function. Also known as colitis, mucous colitis, spastic colon, nervous colon, and spastic bowel.
A complex sugar found in milk and milk products. Lactose must be broken down into the simple sugars galactose and glucose to be absorbed. Lactase is the intestinal enzyme that is needed to digest lactose.
Lactose intolerance
A common condition in which a person does not produce enough lactase to digest the lactose in milk or milk products. It is commonly associated with abdominal cramping and diarrhea after drinking milk or eating dairy products. Over 80 percent of nonwhite adults have this.
Large intestine
The part of the intestinal tract that extends from the ileum to the anus. The large intestine is divided into the appendix, cecum, colon (ascending, transverse, descending, and sigmoid), rectum, and anus.
Lower GI series
An x ray that requires insertion of barium into the large intestine to make it show up better. Also called a barium enema x ray.
low FODMAP Diet
A diet managed by a Dietitian which is used to investigate a patient’s limits for foods containing FODMAPs
A condition in which the intestine has a less than normal ability to digest or absorb foodstuffs, which reduces the nutrients a person receives. Unabsorbed food may cause diarrhea and gas.
Medical Foods (Prescription)
Medical foods are regulated by the FDA under the Orphan Drug Act. They provide specific nutrients needed to manage a specific condition or disease.
The ability to move; in this case, all movements of the intestines.
A clear, sticky discharge made by the intestines. It coats and protects tissues in the GI tract.
Nocturnal pain
Pain that occurs during the night.
Blockage or clogging of a vessel, duct, etc., that prevents liquids or solids from flowing through the area and results in a buildup of pressure above the obstruction.
Progressive wavelike muscular contractions that move materials through the upper GI tract
Inflammation of the rectum lining.
A doctor who specializes in treating disorders of the anus and rectum.
The extreme lower end of the large intestine leading to the anus.
A backward flow: regurgitation.
The backward flow of gas, gastric juice, or small amounts of food from the stomach to the mouth.
The acronym for a condition called Small Intestine Bacteria Overgrowth which refers to an accumulation of excessive amounts of gut bacteria in the small intestine.
A rigid or flexible endoscope used to look into the anus, rectum, and sigmoid colon.
Small bowel enema
A diagnostic procedure in which a tiny tube is passed through the nose or mouth and placed in the upper part of the small intestine. A small amount of barium liquid is injected through the tube and observed on a fluoroscope as it passes through the small intestine.
Small bowel follow through
A diagnostic procedure in which x-rays are taken of the small intestine as the barium liquid passes through it.
Small intestine
The largest part of the digestive tube that connects the stomach to the large intestine. The small intestine is divided into the duodenum, jejunum, and ileum and is the site where most of the digestion and food absorption occurs.
Feces; the waste matter discharged from the anus.
An open sore on the skin surface or on a mucous surface such as the lining of the stomach.
Ulcerative colitis
A chronic inflammatory disease of the large intestine (colon) lining.
Ultrasound imaging
A diagnostic test in which sound pulses are sent into the body. The returning echoes are collected and a picture is produced from them. Ultrasound uses the same technology as sonar.
Upper GI series (barium meal)
A diagnostic procedure in which x-rays are taken after the patient swallows a liquid containing barium. The barium liquid helps to outline the esophagus, stomach, and duodenum so that they show us dearly on x-ray.
Vagus nerve
The nerves to the stomach that play a role in the production of stomach acid.


National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Last updated on Dec 10, 2019