Amylase: an enzyme produced in the pancreas and salivary glands that helps in the digestion of starches from the diet. Blood amylase levels might be increased in patients who have pancreatitis.

Amyloidosis: a group of diseases that result from the abnormal deposition of a protein called amyloid in tissues and organs.

Banding: rubber bands placed on esophageal varices (enlarged vessels) at the time of an esophagogastroduodenoscopy (EGD) — This can be done to stop bleeding from varices or to prevent future bleeding.

Bezoar: a clump of food or hair in the digestive tract. Bezoars can cause obstructions in the stomach that keep food from passing into the small intestine.

Celiac disease: a disease resulting from the abnormal reaction by the body's immune system to gluten, a protein found in many grains, such as wheat, rye, and barley, and other foods. In people who have celiac disease, the immune system causes damage to the small intestine and prevents the proper absorption of nutrients from food. Symptoms include diarrhea and weight loss.

Duodenum: the first part of small intestine.

Elastase: an enzyme found in fluids produced by the pancreas. It aids in the digestion of several proteins, including elastin, an elastic substance in the lungs and other organs that is part of their structural framework. Normally, elastase is inhibited by a substance called alpha-1 antitrypsin.

Electrogastrography (EGG): a diagnostic test that measures electrical activity in the stomach using electrodes placed on the skin.

Endoscopy: a procedure that uses a flexible, lighted tube to look inside the body. The instrument is introduced into the body through a natural opening such as the mouth or anus.

Endoscopic ultrasound (EUS): a procedure that combines endoscopy and ultrasound, and allows a doctor to obtain images and information about the digestive tract, and the surrounding tissue and organs. This test is used to look deeper into the tissue of the bowel for any abnormalities.

Endoscopic retrograde cholangiopancreatography (ERCP): a procedure during which a tube is placed down the patient's throat, into the stomach, then into the small intestine. Dye is injected and the ducts of the gallbladder, liver, and pancreas, and can be seen on X-ray. The procedure might be performed to diagnose and treat problems in the liver, gallbladder, bile ducts, and pancreas, including gallstones, inflammatory strictures (scars), leaks (from trauma and surgery), and cancer.

Gastrin: a hormone that causes the stomach to produce too much acid, which causes stomach and duodenal ulcers.

Gastrinoma: a tumor that develops in the pancreas of patients with Zollinger-Ellison syndrome. Gastrinomas secrete the hormone gastrin.

Gastroesophageal reflux: a condition in which the liquid stomach contents back up into the esophagus. This then produces symptoms of heartburn or regurgitation.

Gastroparesis: paralysis of the stomach, so that the stomach cannot empty itself of food in a normal fashion.

Gastrostomy tube: a feeding tube placed in the stomach during an EGD. This is also commonly called a PEG (percutaneous endoscopic gastrostomy).

H2 blockers: a group of digestive disease drugs that relieve acid reflux and pain by suppressing the production of stomach acid.

Hemorrhoid: clumps of tissue within the anus that contain blood vessels and their supporting tissue.

Hemorrhoidectomy: surgery to remove hemorrhoids.

HIDA scan (or cholescintigraphy): a test during which a radioactive material called hydroxy iminodiacetic acid (HIDA) is injected into the patient. The test is used to diagnose obstruction of the bile ducts by a gallstone or tumor and leaks of bile from the bile ducts.

Jaundice: a yellowing of the skin and whites of the eyes that occurs when levels of the pigment bilirubin are abnormally high. This might occur when the liver is not working properly or when a bile duct is blocked.

Jejunostomy tube: a feeding tube that is inserted during a surgical procedure through the abdomen into the part of the small intestine called the jejunum. Nutrients are put into the tube to feed the patient who is unable to swallow.

Laparoscopic surgery: "minimally invasive" surgery during which small (usually 5- to 10-millimeter) incisions are made. The laparoscope and surgical instruments are inserted through these incisions. The surgeon is guided by the laparoscope, which transmits a picture of the internal organs on a monitor.

Lipase: an enzyme produced in the pancreas and secreted into the small intestine that aids in the digestion of certain fats from food.

Liver function tests (LFTs), also known as liver blood tests: blood tests that can show evidence of conditions affecting the normal functioning of the liver, gallbladder, or bile ducts.

Pancreatitis: inflammation of the pancreas.

Parenteral nutrition: a feeding method during which nutrients go directly into the bloodstream through a catheter placed into a vein.

Proton pump inhibitors: drugs that suppress acid production in the stomach by blocking the enzyme in the stomach that produces acid.

Sclerotherapy: a procedure during which a chemical irritant solution is injected into a vein to sclerose or harden it by causing scar formation. This forces the blood flow to nearby healthy blood vessels. Sclerotherapy might be done to treat hemorrhoids, esophageal varices, varicose and spider veins.

Secretin: a hormone made in the small intestines that aids in digestion.

Secretin stimulation test: a test that measures the ability of the pancreas to respond to the hormone secretin.

Ultrasound: the use of high-frequency sound waves to produce images of the organs and structures inside the body.

Vagus nerve, also called cranial nerve X: the nerve that regulates the function of numerous organs of the body from the throat and voice box to the trachea (windpipe), lungs, heart, and most of the intestinal tract. It also brings sensory information to the brain from the ears, tongue, and throat.

Villi: hair-like structures that line the small intestine and absorb nutrients from food.

Zollinger-Ellison syndrome: a rare disorder of the gastrointestinal system caused by a tumor called a gastrinoma. Gastrinomas most often occur in the pancreas. The tumor secretes the hormone gastrin, which increases acid levels in the stomach, leading to severe, recurrent ulcers of the esophagus, stomach, and intestines.

Last reviewed by a Cleveland Clinic medical professional on 01/30/2014.

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