Calculi
Stones or solid lumps such as gallstones.

Campylobacter pylori
The original name for the bacterium that causes ulcers. The new name is Helicobacter pylori. See also Helicobacter pylori.

Candidiasis
A mild infection caused by the Candida (KAN-di-duh) fungus, which lives naturally in the gastrointestinal tract. Infection occurs when a change in the body, such as surgery, causes the fungus to overgrow suddenly.

Carbohydrates
One of the three main classes of food and a source of energy. Carbohydrates are the sugars and starches found in breads, cereals, fruits, and vegetables. During digestion, carbohydrates are changed into a simple sugar called glucose. Glucose is stored in the liver until cells need it for energy.

Caroli's Disease
An inherited condition. Bile ducts in the liver are enlarged and may cause irritation, infection, or gallstones.

Cathartics
See Laxatives.

Catheter
A thin, flexible tube that carries fluids into or out of the body.

Cecostomy
A tube that goes through the skin into the beginning of the large intestine to remove gas or feces. This is a short-term way to protect part of the colon while it heals after surgery.

Cecum
The beginning of the large intestine. The cecum is connected to the lower part of the small intestine, called the ileum.

Celiac Disease
Inability to digest and absorb gliadin, the protein found in wheat. Undigested gliadin causes damage to the lining of the small intestine. This prevents absorption of nutrients from other foods. Celiac disease is also called celiac sprue, gluten intolerance, and nontropical sprue.

Celiac Sprue
See Celiac Disease.

Chlorhydria
Too much hydrochloric acid in the stomach.

Cholangiography
A series of x-rays of the bile ducts.

Cholangitis
Irritated or infected bile ducts.

Cholecystectomy
An operation to remove the gallbladder.

Cholecystitis
An irritated gallbladder.

Cholecystogram, Oral
An x-ray of the gallbladder and bile ducts. The patient takes pills containing a special dye to make the organs show up in the x-ray. Also called oral cholecystography.

Cholecystography, Oral
See Cholecystogram, Oral.

Cholecystokinin
A hormone released in the small intestine. Causes muscles in the gallbladder and the colon to tighten and relax.

Choledocholithiasis
Gallstones in the bile ducts.

Cholelithiasis
Gallstones in the gallbladder.

Cholestasis
Blocked bile ducts. Often caused by gallstones.

Cholesterol
A fat-like substance in the body. The body makes and needs some cholesterol, which also comes from foods such as butter and egg yolks. Too much cholesterol may cause gallstones. It also may cause fat to build up in the arteries. This may cause a disease that slows or stops blood flow.

Chronic
A term that refers to disorders that last a long time, often years.

Chyme
A thick liquid made of partially digested food and stomach juices. This liquid is made in the stomach and moves into the small intestine for further digestion.

Cirrhosis
A chronic liver condition caused by scar tissue and cell damage. Cirrhosis makes it hard for the liver to remove poisons (toxins) like alcohol and drugs from the blood. These toxins build up in the blood and may affect brain function.

Clostridium difficile (C. difficile)
Bacteria naturally present in the large intestine. These bacteria make a substance that can cause a serious infection called pseudomembranous colitis in people taking antibiotics.

Colectomy
An operation to remove all or part of the colon.

Colic
Attacks of abdominal pain, caused by muscle spasms in the intestines. Colic is common in infants.

Colitis
irritation of the colon.

Collagenous Colitis
A type of colitis. Caused by an abnormal band of collagen, a thread-like protein.

Colon
See Large Intestine.

Colonic Inertia
A condition of the colon. Colon muscles do not work properly, causing constipation.

Colonoscopy
A test to look into the rectum and colon. The doctor uses a long, flexible, narrow tube with a light and tiny lens on the end. This tube is called a colonoscope.

Colonoscopic Polypectomy
The removal of tumor-like growths (polyps) using a device inserted through a colonoscope.

Colon Polyps
Small, fleshy, mushroom-shaped growths in the colon.

Coloproctectomy
See Proctocolectomy.

Colorectal Cancer
Cancer that occurs in the colon (large intestine) or the rectum (the end of the large intestine). A number of digestive diseases may increase a person's risk of colorectal cancer, including polyposis and Zollinger-Ellison Syndrome.

Colorectal Transit Study
A test to see how food moves through the colon. The patient swallows capsules that contain small markers. An x-ray tracks the movement of the capsules through the colon.

Colostomy
An operation that makes it possible for stool to leave the body after the rectum has been removed. The surgeon makes an opening in the abdomen and attaches the colon to it. A temporary colostomy may be done to let the rectum heal from injury or other surgery.

Common Bile Duct
The tube that carries bile from the liver to the small intestine.

Common Bile Duct Obstruction
A blockage of the common bile duct, often caused by gallstones.

Computed Tomography (CT) Scan
An x-ray that produces three-dimensional pictures of the body. Also known as computed axial tomography (CAT) scan.

Constipation
A condition in which the stool becomes hard and dry. A person who is constipated usually has fewer than three bowel movements in a week. Bowel movements may be painful.

Continence
The ability to hold in a bowel movement or urine.

Continent Ileostomy
An operation to create a pouch from part of the small intestine. Stool that collects in the pouch is removed by inserting a small tube through an opening made in the abdomen. See also Ileostomy.

Corticosteroids
Medicines such as cortisone and hydrocortisone. These medicines reduce irritation from Crohn's disease and ulcerative colitis. They may be taken either by mouth or as suppositories.

Crohn's Disease
A chronic form of inflammatory bowel disease. Crohn's disease causes severe irritation in the gastrointestinal tract. It usually affects the lower small intestine (called the ileum) or the colon, but it can affect the entire gastrointestinal tract. Also called regional enteritis and ileitis. See also Inflammatory Bowel Disease (IBD) and Granuloma.

Cryptosporidia
A parasite that can cause gastrointestinal infection and diarrhea. See also Gastroenteritis.

Cyclic Vomiting Syndrome (CVS)
Sudden, repeated attacks of severe vomiting (especially in children), nausea, and physical exhaustion with no apparent cause. Can last from a few hours to 10 days. The episodes begin and end suddenly. Loss of fluids in the body and changes in chemicals in the body can require immediate medical attention. Also called abdominal migraine.

Cystic Duct
The tube that carries bile from the gallbladder into the common bile duct and the small intestine.

Cystic Duct Obstruction
A blockage of the cystic duct, often caused by gallstones.