Gastroenterology (GI) Glossary of Terms

Acid Reflux – Upward ejection of acid from the stomach into the esophagus, causing pain known as heartburn.

Adenoma-A benign tumor of a glandular structure or of glandular origin.

Abdominal Abscess- A pocket of pus, usually caused by a bacterial infection; A pocket of infected fluid and pus located inside the belly (abdominal cavity.)

Ascites-Abnormal accumulation of serous fluid in the spaces between tissues and organs in the cavity of the abdomen.

Barium- A metallic element in the alkaline earths. In medicine, a chalky solution of barium is used to coat the inside of organs, such as the stomach or intestines so that they will show up on an x-ray.

Biliary System- The organs and ducts that make and store bile (a fluid made by the liver that helps digest fat), and release it into the small intestine. It includes the gallbladder and bile ducts inside and outside the liver. Also called Biliary Tract.

Biopsy- The removal of cells, fluids or tissues for examination by a pathologist.

Carcinoma- A type of cancer that starts in cells that make up the skin or the tissue lining organs, such as the liver or kidneys. Like other types of cancer, carcinomas are abnormal cells that divide without control. They are able to spread to other parts of the body, but don't always.

CAT Scan- A cross-sectional, three-dimensional (3-D) image of an internal body part to help diagnose, plan treatment or find out how well treatment is working. Pictures are taken from different angles and are used to create 3-D views of tissues and organs. A dye may be injected into a vein or swallowed to help the tissues and organs show up more clearly. 

Celiac Disease- A digestive disease that is caused by an immune response to a protein called gluten, which is found in wheat, rye, barley and oats. Celiac disease damages the lining of the small intestine and interferes with the absorption of nutrients from food. A person with celiac disease may become malnourished no matter how much food is consumed.

Cholecystectomy- Surgical removal of the gallbladder, the pear-shaped organ that sits just below your liver and collects and stores bile.

Cirrhosis- A type of chronic, progressive liver disease in which liver cells are replaced by scar tissue.

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

Colon- The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food.

Colitis- Inflammation of the colon.

Colonoscopy- Endoscopic examination of the colon.

Constipation- A condition in which stool becomes hard, dry and difficult to pass, and bowel movements don’t happen very often.

Crohn’s disease- Chronic inflammation that typically involves the lower portion of the ileum, often spreads to the colon, and is characterized by diarrhea, cramping, loss of appetite and weight, and the development of abscesses and scarring.

Diarrhea- Frequent and watery bowel movements.

Diaphragm- The thin muscle below the lungs and heart that separates the chest from the abdomen.

Corticosteroids- A group of steroid hormones produced in the adrenal cortex or made synthetically. They have various metabolic functions and some are used to treat inflammation.

Endoscopy- A procedure that uses an endoscope to examine the inside of the body. An endoscope is a thin, tube-like instrument that has a light and a lens, and may be a tool to remove tissue. 

Esophagus- The muscular tube through which food passes from the throat to the stomach.

Fecal Incontinence- Inability to hold stool in the rectum.

Fistula- An abnormal opening or passage between two organs or between an organ and the surface of the body. 

Flexible Sigmoidoscopy- An exam used to evaluate the lower part of the colon. During a flexible sigmoidoscopy exam, a sigmoidoscope (a thin, tube-like instrument that has a light and a lens, and may be a tool to remove tissue) is inserted into the rectum.

Fecal Occult Blood Test- A lab test used to check stool samples for hidden (occult) blood. Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum.

Gallbladder- The pear-shaped organ found below the liver that collects and stores bile.

Gallstone- Solid material that forms in the gallbladder or common bile duct. Gallstones are made of cholesterol or other substances found in the gallbladder.

Gastroesophageal reflux disease (GERD) – Unusually frequent or chronic reflux of stomach contents into the esophagus, resulting in heartburn.

Esophageal Manometry- A test to assess motor function of the upper esophageal sphincter, esophageal body and lower esophageal sphincter.

Heartburn-A burning discomfort behind the lower part of the sternum due to the reflux of acid from the stomach into the esophagus.

Helicobacter Pylori (h-pylori)- A gram-negative, microaerophilic bacterium usually found in the stomach.

Hemorrhoids- An abnormal mass of dilated and engorged blood vessels in swollen tissue that occurs internally in the anal canal or externally around the anus, that may be marked by bleeding, pain or itching.

Hepatitis- A disease or condition marked by inflammation of the liver.

Hiatal Hernia- Occurs when part of the stomach bulges into the chest. It can cause severe heartburn but is treatable.

Ileostomy- Surgical formation of an artificial anus by connecting the ileum to an opening in the abdominal wall.

Inflammatory Bowel Disease- A general term that refers to the inflammation of the colon and rectum. Inflammatory bowel disease includes ulcerative colitis and Crohn’s disease.

Irritable Bowel Syndrome- A disorder of the intestines commonly marked by abdominal pain, bloating and changes in a person’s bowel habits. This may include diarrhea or constipation, or both, with one occurring after the other.

Jaundice- A condition in which the skin and the whites of the eyes become yellow, urine darkens and the color of stool becomes lighter than normal. Jaundice occurs when the liver is not working properly or when a bile duct is blocked.

Lactase- An enzyme that breaks down lactose, a type of sugar found in milk and milk products.

Lactose-Intolerance- The inability to digest lactose, a component of milk and some other dairy products. The basis for lactose intolerance is the lack of an enzyme called lactase in the small intestine. The most common symptoms of lactose intolerance are diarrhea, bloating and gas.

Laparoscopy- A procedure that uses a laparoscope, inserted through the abdominal wall, to examine the inside of the abdomen.

Large Intestine- The long, tube-like organ that is connected to the small intestine at one end and the anus at the other. The large intestine has four parts: cecum, colon, rectum and anal canal.

Small Intestine- A long tube-like organ that connects the stomach and the large intestine. It is about 20 feet long and folds many times to fit inside the abdomen. The small intestine has three parts: the duodenum, jejunum and ileum. 

Laxative- A substance that promotes bowel movements.

Liver- A large organ located in the upper abdomen. The liver cleanses the blood and aids in digestion by secreting bile.

MRI- A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue.

Nausea- A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

Nitrates- Any salt or ester of nitric acid. Some individuals have sensitivity to nitrates and may suffer from headache, diarrhea or urticaria after ingesting them.

Occult Blood- Blood that is present in amounts too small to be seen and can be detected only by chemical analysis or microscopic examination.

Pancreas- A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones, including insulin.

Pancreatic Cancer- A disease in which malignant (cancer) cells are found in the tissues of the pancreas. 

Pancreatitis- Inflammation of the pancreas. Chronic pancreatitis may cause diabetes and problems with digestion. Pain is the primary symptom.

Paracentesis- A procedure in which a thin needle or tube is put into the abdomen to remove fluid from the peritoneal cavity (the space within the abdomen that contains the intestines, stomach and liver.)

Pathology- The scientific study of the nature, origin, progress and cause of a disease. May sometimes be used to make a diagnosis of a disease.

Peptic Ulcer Disease- A sore that develops on the lining of the esophagus, stomach or small intestine. This happens when your stomach acids etch away your digestive tract’s protective layer of mucus.

Peristalsis- The rippling motion of muscles in the intestine or other tubular organs characterized by the alternate contraction and relaxation of the muscles that propel the contents onward.

Polyps- An abnormal growth of tissue projecting from a mucous membrane. Polyps are usually benign, but some may become malignant or cancerous.

Portal Hypertension (Colon)- High blood pressure in the vein that carries blood to the liver from the stomach, small and large intestines, spleen, pancreas and gallbladder. It is usually caused by a block in the blood flow through the liver due to cirrhosis (scarring) of the liver.

Proctosigmoidectomy- Complete or partial surgical excision of the rectum and sigmoid colon.

Rectal Bleeding- The passage of bright blood (often mixed with clots or stools) via the rectum. 

Rectum- The last several inches of the large intestine closest to the anus.

Sphincteroplasty- The surgical reconstruction of a sphincter muscle. This usually refers to the procedure that can be done on the muscles of the anal sphincter that control bowel movements. With obstetric trauma during vaginal delivery of a baby, this sphincter can become damaged and result in incontinence of stool.

Stoma- A surgically created opening from an area inside the body to the outside.

Stomach- An organ that is part of the digestive system. The stomach helps digest food by mixing it with digestive juices and churning it into a thin liquid.

Dysphagia- Difficulty swallowing.

Thrombosis- The formation or presence of a thrombus (blood clot) inside a blood vessel.

Total Abdominal Colectomy- The removal of the large intestine from the lowest part of the small intestine (ileum) to the rectum. After it is removed, the end of the small intestine is sewn to the rectum.

Trocar- A sharp-pointed surgical instrument fitted with a cannula and used to insert the cannula into a body cavity as a drainage outlet.

Ulcerative Colitis- Chronic inflammation of the colon that produces ulcers in its lining. This condition is marked by abdominal pain, cramps and loose discharges of pus, blood and mucus from the bowel.

Ulcers- A break on the skin, in the lining of an organ or on the surface of a tissue. An ulcer forms when the surface cells become inflamed, die and are shed. Ulcers may be linked to cancer and other diseases.

Ultrasound- A procedure that uses high-energy sound waves to look at tissues and organs inside the body. The sound waves make echoes that form pictures of the tissues and organs on a computer screen (sonogram).

Urea Breath Test- A rapid diagnostic procedure used to identify infections by helicobacter pylori (h-pylori), a spiral bacterium implicated in gastritis, gastric ulcer and peptic ulcer disease. It is based upon the ability of h-pylori to convert urea to ammonia and carbon dioxide.

Variceal Bleeding- Bleeding from varices is a medical emergency. If the bleeding is not controlled quickly, a person may go into shock or die. Even after the bleeding has been stopped, there can be serious complications, such as pneumoniasepsisliver failurekidney failure, confusion and coma.

Varices- Varices are dilated blood vessels in the esophagus or stomach caused by portal hypertension

Vomiting- The forceful expulsion of the contents of the stomach via the mouth or sometimes the nose.