Abdomen
The area between the chest and the hips. Contains the stomach, small intestine, large intestine, liver, gallbladder, pancreas, and spleen.

Abdominal Migraine
See Cyclic Vomiting Syndrome.

Absorption
The way nutrients from food move from the small intestine into the cells in the body.

Accessory Digestive Organs
Organs that help with digestion but are not part of the digestive tract. These organs are the tongue, glands in the mouth that make saliva, pancreas, liver, and gallbladder.

Achalasia
A rare disorder of the esophagus. The muscle at the end of the esophagus does not relax enough for the passage to open properly.

Achlorhydria
A lack of hydrochloric acid in stomach juice.

Acid Perfusion Test
The Bernstein test attempts to reproduce symptoms of heartburn. It is usually done along with other tests dealing with esophageal functions. A nasogastric tube will be inserted through your nostril and down into your esophagus. An infusion of mild hydrochloric acid is introduced through the tube, alternating with a saline solution, and you will be asked to report any discomfort you experience during the test.

Activated Charcoal
An over-the-counter product that may help relieve intestinal gas.

Acute
A disorder that is sudden and severe but lasts only a short time.

Aerophagia
A condition that occurs when a person swallows too much air. Causes gas and frequent belching.

Alactasia
An inherited condition causing the lack of the enzyme needed to digest milk sugar.

Alagille Syndrome
A condition of babies in their first year. The bile ducts in the liver disappear, and the bile ducts outside the liver get very narrow. May lead to a buildup of bile in the liver and damage to liver cells and other organs.

Alimentary Canal
See Gastrointestinal (GI) Tract.

Allergy
A condition in which the body is not able to tolerate certain foods, animals, plants, or other substances.

Ambulatory pH Monitoring & Bravo Wireless pH Monitoring

Amebiasis
An acute or chronic infection. Symptoms vary from mild diarrhea to frequent watery diarrhea and loss of water and fluids in the body. See also Gastroenteritis.

Amino Acids
The basic building blocks of proteins. The body makes many amino acids. Others come from food and the body breaks them down for use by cells. See also Protein.

Anal Fissure
A small tear in the anus that may cause itching, pain, or bleeding.

Anal Fistula
A channel that develops between the anus and the skin. Most fistulas are the result of an abscess (infection) that spreads to the skin.

Anastomosis
An operation to connect two body parts. An example is an operation in which a part of the colon is removed and the two remaining ends are rejoined.

Anemia
Not enough red blood, red blood cells, or hemoglobin (HEE-muh-gloh-bin) in the body. Hemoglobin is a protein in the blood that contains iron.

Angiodysplasia
Abnormal or enlarged blood vessels in the gastrointestinal tract.

Angiography
An x-ray that uses dye to detect bleeding in the gastrointestinal tract.

Anorectal Atresia
Lack of a normal opening between the rectum and anus.

Anorectal Manometry & Faecal Incontinence

Anoscopy
A test to look for fissures, fistulae, and hemorrhoids. The doctor uses a special instrument, called an anoscope, to look into the anus.

Antacids
Medicines that balance acids and gas in the stomach. Examples are Maalox, Mylanta, and Di-Gel.

Anticholinergics
Medicines that calm muscle spasms in the intestine. Examples are dicyclomine, (Bentyl) and hyoscyamine (Levsin).

Antidiarrheals
Medicines that help control diarrhea. An example is loperamide (lo-PEH-ruh-myd) (Imodium).

Antiemetics
Medicines that prevent and control nausea and vomiting. Examples are promethazine (pro-MEH-thuh-zeen) (Phenergan) and prochlorperazine (pro-klor-PEH-ruh-zeen) (Compazine).
Antispasmodics
Medicines that help reduce or stop muscle spasms in the intestines. Examples are dicyclomine (dy-SY-klo-meen) (Bentyl) and atropine (AH-tro-peen) (Donnatal).

Antrectomy
An operation to remove the upper portion of the stomach, called the antrum. This operation helps reduce the amount of stomach acid. It is used when a person has complications from ulcers.

Anus
The opening at the end of the digestive tract where bowel contents leave the body.

Appendectomy
(AP-en-DEK-tuh-mee)
An operation to remove the appendix.

Appendicitis
(uh-PEN-duh-SY-tis)
Reddening, irritation (inflammation), and pain in the appendix caused by infection, scarring, or blockage.

Appendix
(uh-PEN-diks)
A 4-inch pouch attached to the first part of the large intestine (cecum). No one knows what function the appendix has, if any.

Ascending Colon
The part of the colon on the right side of the abdomen.

Ascites
A buildup of fluid in the abdomen. Ascites is usually caused by severe liver disease such as cirrhosis.

Asymptomatic
The condition of having a disease, but without any symptoms of it.

Atonic Colon
Lack of normal muscle tone or strength in the colon. This is caused by the overuse of laxatives or by Hirschsprung's disease. It may result in chronic constipation. Also called lazy colon. See Hirschsprung's Disease.

Atresia
Lack of a normal opening from the esophagus, intestines, or anus.

Atrophic Gastritis
Chronic irritation of the stomach lining. Causes the stomach lining and glands to wither away.

Autoimmune Hepatitis
A liver disease caused when the body's immune system destroys liver cells for no known reason.