To find a specific term or abbreviation, click the starting letter of the term or abbreviation.


A – C  |  D – F  |  G – I  | J – L  | M – O  | P – R  | S – U  | V – Z

A – C

Acid Reflux A condition in which contents from the stomach come back up into the esophagus and is often accompanied by a painful sensation behind the breast bone called “heartburn.”

Abdomen Also called the “belly,” this is the part of the body that includes the area approximately from the chest to the hips.

Adhesion Scar tissue that forms on the external surface of the intestine causing it to become stuck to an adjacent structure. Adhesions may cause partial obstructions by deforming part of the intestinal tract and may form after an abdominal operation.

Adrenal insufficiency, primary Adrenal glands produce insufficient quantities of regulatory hormones leading to low blood pressure, low blood sugar and fatigue (weakness) particularly during times of illness.

Adrenal insufficiency, secondary Adrenal insufficiency related to long-term systemic steroid use. Symptoms similar to primary adrenal insufficiency.

Allergen A protein that induces an immediate (IgE) or late (cell mediated) allergic reaction.

Allergic Rhinitis Sneezing, stuffy and/or runny nosetriggered by inhaledallergens.

Allergist A physician who specializes in diagnosis and treatment of allergic disorders, including asthma, allergic skin rashes, allergic rhinitis, and food allergies.

Allergy An abnormal immune system response to any stimulus that can take any of 4 different types of reaction characteristics (Immediate/IgE-Mediated, Cytotoxic, Immune Complex-Mediated or Delayed/Cell-Mediated); the classic working definition used by most physicians only includes immediate response allergic reactions (IgE-Mediated).

Amino Acid Amino acids are the building blocks of all proteins.  Some amino acids also function as chemical signals, such as neurotransmitters.

Amylase The digestive enzyme needed to digest starches (complex carbohydrates). This enzyme is produced by the pancreas and is also found in the saliva.

Anal Fissure A crack in the skin tissue of the anus. Fissures may bleed and become irritated or infected with bowel movements, therefore good hygiene habits are necessary.

Anemia Anemia refers to low red blood cell and low hemoglobin level count.  There are many causes of anemia, the most common of which is iron deficiency.

Anorexia Loss of appetite from any cause. It can have physiologic and/or psychologic components.

Anorexia Nervosa A psychological disorder of body image in which the individual feels overweight regardless of actual weight. Persons affected by this disorder have a fear of gaining weight and may use excessive exercise, laxatives and/or skipping of meals in order to achieve what they perceive as an ideal body weight and image. Complications may include nutritional deficiencies, osteoporosis, organ dysfunction or failure, and in extreme cases, coma and/or death.

Antihistamine A medication that blocks the action of histamine in the body. Typical uses of Histamine subtype 1 blockers (H1 Blockers) include stopping or decreasing allergic reactions such as hives, allergic rhinitis, and/or eczema, decreasing nausea and dizziness associated with motion sickness or chemotherapy drugs, and helping with sleep problems. Non-sedating antihistamines are relatively new and are used  for daytime allergy sufferers. Typical uses for histamine subtype 2 blockers (H2 Blockers) which block acid effects include stomach ulcers, heartburn and GERD.

Anus An opening in the rectum that allows stool to move out of the body (bowel movement). Common problems with the anus are hemorrhoids, abscesses, and fissures (cracks), and cancer.

Appendicitis An infection of the appendix with symptoms such as severe pain in the lower right part of the abdomen, nausea, vomiting, and/or fever; surgical removal of the appendix should be done immediately to prevent a bursting of the infected appendix.

Appendix The appendix is found at the junction between the large intestine and the small intestine, and is usually found in the lower right side of the abdomen. It has no known function. It is removed surgically if it becomes inflamed/infected (appendicitis).

Ascending Colon The part of the large intestine located on the right side of the abdomen that attaches the cecum with the hepatic flexure at the start of the transverse colon.

Ascites A collection of fluid in the abdomen.

Asthma A disorder causing the airways to become inflamed and narrowed due to mucous production and leads to symptoms of wheezing, shortness of breath, coughing and chest tightness. Asthma is can be triggered by an inhaled allergen.

Asymptomatic Absence of symptoms.

Autoimmune Disease A disease in which a part of the body’s immune system attacks its own cells that make up part of the body, such as skin, connective or joint tissue, intestinal tissue, nerve cells , etc.

Barium Swallow A test in which X-rays are taken after one has swallowed some a liquid radio-contrast material called barium. The test is used to diagnose and determine the extent of swallowing problems. See also Upper GI X-Ray.

Barrett’s Esophagus A condition in which the inner lining of the esophagus becomes damaged due to stomach acid refluxing into the lower part of the esophagus. The condition is believed to increase the chances of getting esophageal cancer.

Bile A digestive fluid produced by the liver and stored in the gallbladder. It is needed for proper digestion of fats. Bile is re-absorbed in the small intestine and recycled back to the liver.

Bile Duct A tube that connects the liver and gallbladder to the small intestine. Its function is to allow bile to flow into the small intestine.

Biliary Referring to any duct or organ in the biliary system; the bile ducts, liver and/or gallbladder.

Biopsy A tissue sample. In the case of digestive diseases, the biopsy is usually painless and is taken from the inner layers of the esophagus, stomach, small and large intestines during endoscopy and colonoscopy procedures. See also Full Thickness Biopsy.

Bloating A puffing up of the abdomen, usually caused by excess gas that has accumulated in the small and/or large intestines. Lactose intolerance, irritable bowel syndrome, and other intestinal disorders may increase one’s likelihood of experiencing bloating. Gassy foods such as beans, peanuts, cabbage, cauliflower, broccoli, kale and related foods may lead to bloating from fermentation of a certain carbohydrate that is high in these foods. Also, improper digestion of other nutrients (fats, carbohydrates, proteins) may cause bloating.

Bone Density Test See DEXA Scan.

Candida A species of yeast that is normally present on skin and in intestinal contents.  It can cause superficial infections of the lining of the mouth (called thrush), esophagus, vagina, and skin during or shortly after a courses of antibiotics.  More serious infections of tissues or the blood stream occur in immunocompromised individuals.

Carbohydrate Any substance that has a molecular structure based on sugar, including sugar, glucose, fructose, etc., as well as more complex starches found in plant food sources (fruits, grains, vegetables, etc.).

CAT Scan See CT Scan.

Complete Blood Count (CBC) A blood test that includes a count of all the red and white blood cells, platelets as well as hemoglobin, and hematocrit. Statistics about the red blood cells are also calculated and included in the test results.

Cecum The cecum is the start of the large intestine. Undigested food from the small intestine enter the cecum, and digestion is continued through the large intestine. The cecum is located in the lower right side of the abdomen, and the appendix is attached to the bottom of the cecum.

Celiac Disease (Sprue) An autoimmune disease that damages the inner portion of the small intestine (duodenum), and causes malabsorbtion, causing malnourishment.  The reaction is caused by eating foods that have gluten in them.  Gluten is found in wheat, rye, and barley, and possibly can contaminate oats. Symptoms of celiac disease include nausea, vomiting, intestinal cramping, and malabsorption. These symptoms subside when gluten containing grains are not avoided. The inside of the small intestine has small, finger-like projections called villi, that help with absorption of nutrients. Flattened villi are often associated with the disease, and their appearance on biopsy/endoscopic evaluation is considered the gold standard for diagnosis in a person who is consuming gluten containing foods. Blood antibodies to the gluten and/or gliadin may also assist with diagnosis.

Churg-Strauss Syndrome (CSS) Also known as allergic granulomatosis angiitis. It is a disease of blood vessel inflammation, which can constrict blood flow to organs and tissues causing damage. Eosinophils are part of the inflammatoryprocesss in CSS. This eosinphilic reaction and asthma are the hallmarks of the disease. People may also suffer from sinus problems, neuropathy, rashes, and gastrointestinal issues. 

Clinical Remission Period of time during which signs and symptoms of disease are absent.

Colitis Inflammation of the tissues of the large intestine.

Colon See Large Intestine.

Colonoscopy A procedure in which a long flexible tube is inserted into the rectum. The tube has a light and video camera on the end of it, which allows view of the entire colon, and part of the small intestine. If needed, tissue biopsies of the inside of the colon can be taken, and polyps can be removed through the scope. The colon must be cleaned out before the procedure, to allow a good view of the colon. This is done by using a laxative, driningk liquids, and no food or drink 12 hours before the colonoscopy. A sedative is usually given prior to the procedure.  

Colostomy A surgically created hole in the abdomen in which a part of the colon is brought through to the skin surface. A bag must be worn over the hole to collect bowel movements. A temporary colostomy may be needed to allow some bowel tissue to heal after chronic inflammation has been treated.

Conscious Sedation A combination of medications that help you relax (sedatives), and not feel pain (anesthetic). When under conscious sedation people are able to respond to commands, but usually do not remember the procedure or feel pain. This is used for minor procedures or surgeries.

Corticosteroid See Steroid.

Crohn’s Disease Also called Regional Enteritis, and Regional Ileitis. A chronic inflammatory condition of the digestive track. It is a form of inflammatory bowel disease. It can affect anywhere from the mouth to the anus, and commonly affects the small intestine. It can cause abdominal pain, diarrhea and bleeding from the rectum.

Computed Tomography (CT) Scan, also called Computerized Axial Tomography (CAT Scan), is a special type of X-Ray that results in a series of cross-sectional pictures. CT images are able to show more detail than a regular x-ray. They can show bone and soft tissues, like muscles, vessels, and organs. Sometimes a dye (contrast), is used to help certain areas show up better. The dye is either given through an IV, swallowed, or given through the rectum.

Cushing’s Syndrome Excess cortisol in the body. This may be caused by the body producing too much cortisol, or from taking too much corticosteroid medications.

Cyclical Vomiting Syndrome (CVS) Episodic bouts of vomiting, sometimes severe, interspersed with periods of wellness

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D – F

Descending Colon The part of the large intestine located on the left side of the abdomen that connects the transverse colon at the splenic flexure with the sigmoid colon at the sigmoid flexure.

Degranulation Release of the contents (granules) of the cell. This happens to eosinophils when they are involved, in an immune response in allergic reactions.

Dual Energy X-Ray Absorptiometry (DEXA Scan), a special type of X-ray that can tell the density of bones. The test is painless, just like getting an X-Ray. The typical areas scanned during the test include the hip bone, lumbar spine, and/or the wrist or forearm.

Diaphragm A muscular and connective tissue structure separating the chest and abdominal cavities. The diaphragm contracts and expands in correlation with the lungs during breathing.

Digestive System All of the muscular organs involved in eating, digesting foods and eliminating solid food wastes. This includes the mouth, esophagus, stomach, small intestine, and large intestine.

Duodenitis Inflammation of the duodenum.

Duodenum The upper part of the small intestine that connects the lower part of the stomach with the jejunum.

Dysmotility (Abnormal motility). In reference to the GI tract, food moves more slowly than normal through the esophagus, stomach and/or intestines.

Dyspepsia Discomfort in the stomach marked by symptoms of nausea, loss of appetite, bloating, belching and/or flatulence, change in bowel habits, heartburn, reflux, and/or a gnawing or burning sensation in the stomach area. Causes may include insufficient digestive enzymes or HCl, ulcer, esophageal spasms, intestinal obstruction or other motility problem, IBS, gallstones, lactose intolerance, heart problems, or other causes.

Dysphagia Difficulty swallowing liquid or solid food through any part of the esophagus.

EC Eosinophilic Colitis

Eczema Inflammatory condition of the skin with redness, scaling and often itching. May be related to allergies, infection, diabetes or environmental changes.

Edema Swelling or water retention.

EE Eosinophilic Enteritis

EoE Eosinophilic Esophagitis

Essential Fatty Acid (EFA) The nutritional component of fats and oils found in many foods. There are different types of fatty acids, the most common of which are Omega-3 and Omega-6. Fatty acids are converted in the body to numerous substances critical to our health. Omega-3 fatty acids may be converted into anti-inflammatory immune system components, and Omega-6 fatty acids get converted into anti- and pro-inflammatory immune system components. Consuming these two fatty acids in the proper balance is important for optimum health.

EG Eosinophilic Gastroenteritis

Elemental Formula Nutritionally complete formulas whose protein component is provided as amino acids to reduce the chance of an allergic reaction.   Formulas are used for tube feedings and to decrease the symptoms of food allergy, Eosinophilic Enteritis, Inflammatory Bowel Disease and other diseases.

Elimination Diet A diet in which specific food antigens have been eliminated in order to decrease the chance of having an allergic reaction.

Enzyme-Linked Immunosorbent Assay (ELISA), a type of blood test in which subclasses of immunoglobulins may be detected; the test is used to detect IgE-Mediated (immediate reaction) and IgG-Mediated (delayed reaction) allergies and is helpful in diagnosing some autoimmune diseases such as celiac disease, lupus, rheumatoid arthritis, viral illness and many others.

Endoscope A tube with a light and a camera on the end of it that is used to view the esophagus, stomach, part of the duodenum, part of the terminal ileum and the entire large intestine. Endoscopes usually also contain a biopsy aspiration port for collection of tissue samples during endoscopic procedures. See also Colonoscopy, Endoscopy, Esophagoscopy, and Sigmoidoscopy.

Endoscopy A procedure in which an endoscope is passed through the mouth into the esophagus, stomach and part of the duodenum. Biopsies may be taken of the mucosal layers during this procedure. The patient is typically sedated during the procedure. The only preparation is avoiding all food and liquids for at least 4-8 hours before the procedure.

Enema Administration of medication through the rectum for the purpose of clearing out the bowel.

Enteral Nutrition Nutrition feedings through a tube that either goes through the mouth, nose, stomach or small intestine. The feedings are made of a special liquid that may contain all the nutrients a person needs. Nutrition obtained through the digestive system, either eaten through the mouth or through a feeding tube. See also GJ, GT, JT, ND, NG, and Tube Feeding.

Eosinteritis Inflammation in the tissues of the digestive system, especially the small intestine.

Enzyme Enzymes are a type of catalyst, which means they speed up chemical reactions. In the case of digestive enzymes, they speed up the digestion or breaking down of food into nutritional components such as fatty acids, amino acids, sugars, vitamins and minerals. When the organs which produce digestive enzymes are not producing sufficient quantities, a supplemental form of digestive enzymes may be needed for proper digestion to occur. Some metabolic disorders involve the lack of a certain enzyme needed for processing or metabolizing specific food components.

Eosinophil A type of white blood cell that is specifically involved in allergic reactions (IgE-Mediated), and also seems to be involved in some parasitic infections.

Eosinophilic Colitis (EC) A disease involving patchy infiltration of one or more layers of the large intestine with eosinophils. See also Eosinophilic Enteritis.

Eosinophilic Esophagitis (EoE) A chronic, immune/antigen mediated, esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. 

Eosinophilic Gastroenteritis (EGE) A disease involving patchy infiltration of one or more layers of the stomach and/or small intestine with eosinophils. See also Eosinophilic Enteritis.

Endoscopic Retrograde Cholangiopancreatograph (ERCP), a diagnostic test that uses an endoscope to look at the tubes that drain the liver, gallbladder and pancreas. This is done to look at the health of the tubes and to fix any problems such as a stone blocking the tube or duct.

Erythrocyte A red blood cell.

Esophageal Ring See Schatzki’s Ring.

Esophageal Dilatation A non-surgical procedure that dilates, or stretches, a narrowed part the esophagus (esophageal stricture). This can be done with dilators called bougie dilators or with a balloon.

Esophageal Stricture An area of narrowing of the esophageal lumen.  See also Stricture.

Esophageal Web A membrane that appears in the esophagus, causing dysphagia. The web may be broken via an endoscopic procedure.

Esophagitis Inflammation in the tissue of the esophagus.

Esophagoscopy A procedure in which an endoscope is inserted into the esophagus through the mouth for diagnostic purposes or to perform antireflux surgery, dilate rings or strictures, break up webs, or other necessary procedures.

Esophagus The muscular tube that connects the back of the mouth to the top of the stomach that carries food from the mouth to the stomach.

Erythrocyte Sedimentation Rate (ESR), also called “Sed Rate,” the rate at which red blood cells in a measured sample settle in a specific amount of time. The higher the ESR, the faster the red blood cells settled. An elevated ESR usually indicates inflammation. The ESR is a general measure of inflammation, therefore it does not say anything about the location of the inflammation.

Etiology The cause or triggering factor for development of a specific disease. When a specific etiology is not obvious, the condition is said to be idiopathic.

Failure to Thrive A general term used for insufficient growth (by standard growth charts) or inadequate weight gain caused by a variety of medical and psychosocial conditions.

Fat A dietary substance that is broken down in the body to fatty acids. See also EFA.

Fatty Acid See EFA.

Fecal Impaction When feces, or stool, obstructs colon or rectum, and does not allow waste to pass. It is most commonly seen in people with long-term constipation, and can cause bloating and abdominal pain. This condition usually requires a stool softener or manual disimpaction to alleviate the problem. A diet high in fiber along with sufficient water intake (8-10 glasses of water per day) will usually prevent fecal impaction.

Fistula An abnormal tract formed between loops of bowel, the bowel and other organs or the bowel and the skin surface. Fistulas are normally associated with severe Crohn’s Disease, but might also occur with other inflammatory conditions. Antibiotics and anti-inflammatory medications are typically required for treatment, and placement of a drain or surgical treatment may also be necessary.

Flare A time during which active disease is present.

Flatulance Passing gas through the anus. May be accompanied by bloating, indigestion and/or other symptoms.

Flexible Sigmoidoscope See Sigmoidoscope.

Flexible Sigmoidoscopy See Sigmoidoscopy.

Flexure A normal bend in a tubular body structure such as the large intestines.

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G – I

Gallbladder A saclike organ located just underneath the liver, the gallbladder serves as a storage location for bile that the liver produces.

Gastritis Inflammation of the stomach.

Gastroenterologist A physician who specializes in diagnosing and treating disorders of the digestive system, also including disorders of the liver, spleen and pancreas.

Gastroesophageal Reflux Disease (GERD) A disease in which acid reflux and heartburn occur frequently over an extended period of time.

Gastroparesis Abnormally slow emptying of the contents of the stomach.

GERD See Gastroesophageal Reflux Disease.

Gastro-Intestinal Tract (GI Tract), also called the digestive system.

Gastrojejunostomy Tube (GJ or GJ-Tube), a tube that is surgically inserted through the skin into the stomach and runs to the small intestine. This is done so that liquid food may be pumped directly into the small intestine, bypassing the esophagus and stomach.

Glucocorticoid See Steroid.

Gluten A type of protein found in wheat, rye, barley and possibly oats. People with gluten sensitiviy, gluten intolerance, and Celiac Disease have an adverse reaction when they eat foods that contain gluten

Gluten Intolerance Synonym for celiac disease.

Gastric Tube (GT or G-Tube), a tube that has been surgically inserted through the skin into the stomach so that liquid food may be pumped directly into the stomach bypassing the esophagus.

H. pylori (helicobacter pylori) A bacteria that can cause ulcers in the stomach and duodenum. People with h. pylori infection may not have symptoms, or the may experience abdominal pain, nausea, vomitting, or freqent burping.

Hydrochloric acid (HCL) A component of gastric acid that is produced by cells in the lining of the stomach. This acid helps digest food in the stomach.

Heartburn See Acid Reflux and GERD.

Hepatic Referring to the liver.

Hepatic Flexure The bend in the large intestine that is located on the right side of the abdomen just under the liver and connects the ascending colon with the transverse colon.

Hiatal Hernia A condition in which a small part of the upper stomach pushes through the diaphragm. A sliding hiatal hernia is usually asymptomatic or only causes occasional minor heartburn. A non-sliding hiatal hernia may easily become strangulated, thus requiring surgical correction to prevent potentially serious complications.

Hiccough A spasm of the diaphragm. Also called hiccup.

High Power Field (hpf) Magnified 400-fold under the microscope.

Histamine A chemical your body produces in response to an allergic reaction. It also mediates several other biological activities in the the body. There are 4 histamine receptors (H1-4), that are found on cells. Antihistamines, like Benadryl, block some of the histamine receptors, and relieve symptoms of the allergic reaction.

Hyperplasia An increase in the number of cells in an organ which leads to increased thickness or size of the organ.

Hypoallergenic Low potential to cause allergic reactions.

IBD Inflammatory Bowel Disease

Idiopathic No obvious cause.

Immunoglobulin Antibodies; are produced by the body’s immune system, and attach to foreign substances so the immune system can destroy them. They may attach to bacteria, viruses, fungi, cancer cells, and animal dander. There are 5 major types of antibodies.  IgA Antibodies are found on mucosal surfaces such as the GI tract, airway, nose, mouth and in  body fluids such as tears and saliva. IgE is the allergy antibody. IgG, IgM, and IgD are the other immunoglobulin types.

IgD \ IgD is the first surface antibody produced by B cells
IgE Antibodies are involved in allergic reactions.
IgG Antibodies are found in all body fluids and are important for fighting bacterial and viral infections.
IgM Antibodies are the largest antibodies and are found in blood and lymph fluid. They are the made first to fight infection.

Ileal-Cecal Valve A muscle valve at the connection point between the large and small intestines.

Ileostomy A surgically created hole in the abdomen in which a part of the small intestine is brought through to the skin surface. A bag must be worn over the hole to collect bowel movements. A temporary ileostomy may be needed to allow some bowel tissue to heal after chronic inflammation has been treated.

Ileus A temporary lack of sufficient peristalsis in the intestines. Surgery, intestinal obstruction, infections, and other problems may be the cause. Symptoms typically include abdominal pain, nausea, vomiting, lack of bowel movements and no passing gas.

Ileum The last part of the small intestine, it connects the jejunum with the large intestine.

Immunologist A physician who specializes in diagnosing and treating diseases involving the immune system. Some Immunologists are also called Environmental Medicine Specialists.

Immunomodulator A type of medication, sometimes also known as chemotherapy, that suppresses certain parts of the immune system to achieve disease control. Such medications are typically used in treating autoimmune diseases, cancer and organ transplant rejection.

Indigestion See Dyspepsia.

Inflammation the body’s response to tisse inury, irritation or damage. It is the body’s attempt at self-protection, and this response leads to repair of the damaged tissue. Inflammation can occur anywhere in the body and from many different causes.

Inflammatory Bowel Disease (IBD) A disease in which chronic auto-inflammation of the digestive system occurs; Two specific types of IBD are identified, Crohn’s Disease which can involve the entire gastrointestinal tract  and Ulcerative Colitis which involves only the colon..

Irritable Bowel Syndrome  (IBS), also called “spastic colon.” A disorder in which constipation and/or diarrhea or alternating between the two seems to occur frequently. disorder in which constipation and/or diarrhea, or alternating between the two occur frequently. Inflammation is not part of IBS. It is unknown what causes IBS, but it may be triggered by stress or infection.  There is no known cure.

Intolerance A non-allergic reaction in response to the ingestion of dietary substances.

Intussusception Telescoping or folding of the intestines within itself

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J – L

J-Tube A tube surgically inserted through the skin and into the small intestines to enable liquid feeding (or elemental formula) directly into the small intestine bypassing the esophagus and stomach.

Jejunum The middle part of the small intestine.

JT See J-Tube.

Lactose Intolerance Individuals who are deficient in the intestinal enzyme lactase, do not digest or absorb lactose properly. Malabsorbed lactose reaches the large intestine and is fermented by bacteria. Byproducts of the fermentation process cause symptoms, including gas, diarrhea, nausea, and abdominal cramps and bloating.

Large Bowel See Large Intestine

Large Intestine A long muscular tube that connects the small intestine with the anus. It is responsible for absorption of water from undigestable food.

Lower Esophageal Sphincter (LES), the valve that is located at the bottom of the esophagus  where it is connected to the stomach. Improper function of the LES can cause acid reflux.

Leukotriene A proinflammatory immune system modulator that is released during and after allergic reactions and is also believed to be partly responsible for prolonging other types of inflammation. Leukotrienes are involved in Asthma,and other inflammatory diseases.

Leukotriene Inhibitor A medication that prevents the release of leukotrienes or prevents their proinflammatory action in the body. Several different subtypes of leukotrienes have been identified in association with various inflammatory diseases, hence the development of various different types of leukotriene inhibitor medications.

Lipase The digestive enzyme needed to properly digest lipids, or fats. This enzyme is produced by the pancreas; bile is also needed to digest fats.

Liver The liver is a large solid organ in the right upper corner of the abdomen, and is protected by the rib cage. The liver functions to detoxify chemicals, metabolize drugs, filter blood, and make proteins that are important for blood clotting and other functions. It also produces bile, which is important for digestion, and stores carbohydrates to be used as “fuel” for the body between meals. 

Lower GI Series See Lower GI X-Ray.

Lower GI X-Ray A series of X-rays taken of the large intestine after a liquid solution of barium has been put into the large intestine via enema.

Lumen The hollow portion of a tubular body structure, such as the inside of a blood vessel, the intestines, and the esophagus.

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M – O

Malabsorption Difficulty absorbing nutrients from food or liquids.

Mast Cell A cellular component of the immune system that resides in tissue. When attached to an IgE-Antibody combination, releases mediators (degranulates) of allergic reactions, including leukotrienes, histamine and other chemicals.

Mast Cell Stabilizer A type of medication that helps prevent mast cells from releasing allergic reaction mediators.

Metabolic Disorder a medical condition in which the body has difficulty converting food to energy. Metabolism is complex set of chemical reactions that lead to energy production or storage. People with metabolic disorders have an abnormal chemical reaction that disrupts metabolism.

Motility The coordinated neuromuscular activity of the wall of the GI tract that moves intestinal contents.

Magnetic Resonance Imaging (MRI), a computer-assisted imaging technique that is free of radiation (unlike CT Scans). Sometimes, an MRI may be done using a contrast dye in order to enhance specific body structures. Images are produced in cross-sectional pictures of the part of the body being scanned. MRI Scans are used to view soft tissue and bone, including a wide variety of problems; for example, fractures, tumors, abdominal problems, and some nerve problems can all be examined via MRI.

Mucosa The innermost layer of the esophagus, stomach, small and large intestines. This layer is visible on endoscopic or colonoscopic examination. The submucosa is just underneath the mucosa. The mucosa and submucosa can be biopsied via colonoscopic or endoscopic procedure.
Muscularis The middle layer of the esophagus, stomach, small and large intestines. This layer cannot be biopsied via standard biopsy means. A Full Thickness Biopsy is typically required to obtain a tissue sample containing the muscularis layer.

Narrowing See Stenosis.

Naso-Duodenal Tube (ND or ND-Tube), a tube which is inserted through one nostril of the nose and runs down the esophagus, through the stomach and into the duodenum. Liquid food (or formula) is pumped through the tube directly into the duodenum, bypassing the esophagus and stomach.

Naso-Gastric Tube (NG or NG-Tube), which is a tube that has been inserted into one nostril that runs down the esophagus into the stomach. Liquid food (formula) is pumped through the tube directly into the stomach bypassing the esophagus.

NPO No food by mouth.

Osteopenia A condition in which bone mineral density is lower than normal, but not low enough to be called osteoporosis. Bone mineral density is a measurement of the level of minerals in the bone, and tells how strong and dense the bones are.

Osteoporosis A loss of bone mineral density, leading to weak bones that easily fracture. Some causes include a drop in testosterone or estrogen levels, certain medications, improper nutrition, malabsorption, certain diseases (IBD, Addison’s Disease, Hypothyroid or Hyperparathyroid, etc.), and possibly other causes. Protein deficiency can lead to loss of bone density, as can calcium and other mineral deficiencies. A Bone Density Test (DEXA Scan) is required for diagnosis. Special Osteoporosis medication may be needed to slow the progression of bone density loss.

Ostomy Any type of surgical procedure that creates a hole in the abdominal wall. Examples include ileostomy and colostomy. See also Colostomy, Ileostomy, and Stoma.

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P – R

Pancreas A gland in the body located behind the stomach and extending towards the liver, the pancreas is responsible for producing and secreting some digestive enzymes and also insulin. Diabetes is a disease of the pancreas.

Pancreatic Enzymes Enzymes produced and secreted by the pancreas that are needed for proper digestion.

Pancreatitis Inflammation of the pancreas, sometimes caused by certain medications or alcoholism.

Parasite An organism that has invaded the body that normally does not live in the human body or human digestive system. Some parasites can cause eosinophilic infiltration of the digestive system, resulting in the development of Eosinophilic Enteritis.

Parenteral Nutrition Nutrition obtained through a vein. See also TPN.

Peristalsis Contraction of the muscles in the digestive system in a wavelike fashion, such that foodstuff is moved down from the mouth and through the stomach and intestinal tract for elimination through the rectum. Motility disorders typically cause abnormalities with paristalsis.

Peritoneum A tissue that lines the abdominal wall and covers most of the organs in the abdomen. Peritoneal fluid lines the tissue as a lubricant.

Pernicious Anemia (PA) Classically, PA is only used to describe an autoimmune disease in which the part of the stomach where intrinsic factor is secreted has been attacked by the body’s immune system, rendering Vitamin B12 unabsorbable in the terminal ileum and thus causing anemia. However, some physicians also use PA to describe general Vitamin B12 deficiency regardless of the cause.

Polyp A growth or portion of abnormal tissue that extends from the digestive system wall into the hollow portion of the digestive system. Some are cancerous or pre-cancerous. Some are due to inflammation. Polypectomy may be performed during an endoscopy or colonoscopy procedure.

Polypectomy Removal of a polyp in the digestive system, usually during a colonoscopy or endoscopy procedure. A wire loop is placed over the polyp and then a very low electrical current is passed through the wire as the wire is moved such that the polyp is removed by the movement of the wire through the base of the polyp. The electrical current in the wire helps to cauterize the polyp removal location to reduce bleeding and prevent infection.

Proton Pump Inhibitor (PPI) A medication that blocks the acid producing pumps in the stomach.

Probiotic Bacteria that help maintain the natural balance of the intestine.  This bacteria help reduce the growth of harmful bacteria. These bacteria can be given as a supplemental form of lactobacillus acidophilus, lactobacillus bifidus, some soil-based organisms and/or other bacteria that are known to inhabit healthy small and/or large intestines.

Protease A class of enzyme whose function is to digest other proteins.

Protein A nutritional component required by the body to sustain life. Protein is made up of amino acids that have been connected together in a variety of configurations depending on the type of protein. Whole food proteins are believed to play a role in Eosinophilic Enteritis. See also Amino Acid.

Protein Intolerance Symptoms that develop after an immunologic reaction to one or more dietary proteins.

Protein-Losing Enteropathy An abnormal loss of protien through the digestive tract, resulting in low serum protein (protein in blood).  This may lead to diarrhea, abdominal pain, edema and weight loss.

Pyloric Stenosis Fixed narrowing of the muscle that controls the outlet of the stomach (pylorus) to the small intestine. When the pylorus of the stomach is narrowed, it becomes difficult for food to pass from the stomach to the small intestine. This commonly leads to vomiting.

Pylorus The muscle that surrounds and controls the outlet of the stomach (between the stomach and the duodenum).

Rectum The last part of the large intestine that connects to the anus.

Remission Period of time when no disease activity is present.

Resection Surgical removal of tissue.

Rigid Sigmoidoscope See Sigmoidoscope.
Rigid Sigmoidoscopy See Sigmoidoscopy.

Rotation Diet A way of eating in which related foods are eaten on a rotating schedule. Typically, 3 days are given between eating each item from the same food “family.” The purpose of this type of diet is to promote nutritional variety and to reduce the chances of developing allergies to certain foods.

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S – U

Small Bowel Follow-Through (SBFT), a series of X-rays taken after one drinks a large glass of liquid barium. See also Upper GI X-Ray.

Schatzki’s Ring A buildup of tissue at the lower end of the esophagus that interferes with passage of food.

Sed Rate See ESR.

Sedation Use of medication for a calming effect. Also see conscious sedation.

Serosa a thin membrane that lines body cavities. The serosa of the GI tract is the outermost layer of the intestine. The subserosa is the layer just under the serosa. Both serosa and subserosa cannot be biopsied through an endoscopic or colonoscopic procedure.

Short Bowel Syndrome (SBS) Short Bowel Syndrome refers to the state in which an intestine is too short to normally perform all of its functions, such as nutrient absorption. This results from surgical resection or a birth defect in intestinal development.

Short Gut Syndrome See Short Bowel Syndrome.

Sigmoid Colon A curved part of the large intestine that extends from the rectum to the descending colon on the left side of the abdomen and which includes the sigmoid flexure.

Sigmoidoscope A short, flexible or rigid endoscope designed only to examine the rectum and sigmoid portion of the large intestine.

Sigmoidoscopy A procedure in which a flexible or rigid sigmoidoscope is inserted into the rectum and through the entire length of the sigmoid portion of the large intestine for examination and possible biopsy. Preparation includes an enema and mild laxative to clear waste from the sigmoid and rectal areas. Sedation may be used if needed.

Small Bowel See Small Intestine

Small Intestine A long muscular tube that connects the bottom of the stomach with the large intestine (large bowel).

Splenic Flexure The bend in the large intestine located in the left side of the abdomen (just under the stomach and spleen) where the ascending colon and transverse colon are connected.

Steatorrhea Excess fat in the stool. This may be caused from problems with absorbing fat, which can occur from diseases such as IBD, celiac disease, cystic fibrosis and pancreatic insufficiency.

Stenosis Any type of narrowing of a tubular or hollow structure in the body, such as the intestinal tract or spinal column.

Steroid A type of medication that is a synthetic version of Cortisol or other hormones. When based on Cortisol, this type of medication suppresses the immune system and is therefore used to treat allergies, asthma, EoE, autoimmune diseases, some forms of cancer, organ transplant rejection and other diseases, and to provide adrenal gland support in cases of adrenal insufficiency. If based on Estrogen, it is used as post-menopausal hormone replacement therapy.

Stoma A hole created surgically in the abdominal wall for the purposes of attaching a bag for waste elimination. See also Colostomy, Ileostomy and Ostomy.

Stomach A muscular pouch attached to the bottom of the esophagus where food is stored while it is being prepared for digestion and nutrient extraction in the small intestine.

Stricture An abnormal area of narrowing in the digestive system. This may occur in areas such as the esophagus or colon.

Tenesmus A feeling of needing to pass stool, even when the bowels are empty. With tenesmus there is a spasm of the muscles in the rectum and/or anus that is usually very painful. People with IBD and IBS may experience tenesmus as one symptom of their disease.

Total Parenteral Nutrition (TPN) Complete nutrition (including fat, carbohydrate, animo acids, vitamins, minerals, and water) given as an intravenous infusion.

Transverse Colon The part of the large intestine that connects the hepatic flexure with the splenic flexure and which lies across the abdomen from right to the left.

Tube Feeding Any form of feeding of liquid meals through a tube, including GT, GJ, JT, ND and NG Tubes.

Ulcer An area of variable size and depth in which the lining of the GI tract has eroded away.

Ulcerative Colitis A form of IBD in which inflammation occurs in a contiguous pattern in the inner layers of the large intestine.
Upper GI Series See Upper GI X-Ray and SBFT

Upper GI X-Ray A series of X-rays taken of the esophagus and stomach after one drinks a large glass of liquid barium. If X-rays of the small bowel are also included, it is called an Upper GI X-Ray with Small Bowel Follow-Through.

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V – Z

Villi The tiny fingerlike projections on the inside of the small intestine wall that are responsible for nutrition absorption from the foods we eat. In some diseases, such as Celiac/Sprue and Eosinophilic Gastroenteritis, the villi can appear flattened on endoscopic and/or biopsy evaluation.

White Blood Cell (WBC), a type of blood cell that is involved in the immune system response to invading organisms (bacteria, virus or parasite). The different types of white blood cells include Basophils, Neutrophils, Lymphocytes, Eosinophils and Monocytes.

White Blood Cell Count with Differential (WBC with Diff); a type of blood test in which the total number of white blood cells in a measured amount of blood are counted, and then each of the different types of white blood cells are counted and listed separately in the test results. This is more routinely referred to as a CBC with Diff, and includes RBC/HGB/HCT/Platelets

X-Ray A type of radioactive picture taken of the body that enables the physician to see bones and some soft tissue. A contrast dye, barium or other medium may be used to enhance certain body structures in the X-Ray.

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This document was revised in December 2004. Sources for all of the medical terms and definitions in this document include the Online Merck Manual 17th Edition, Stedman’s Medical Dictionary, 24th edition, and other Internet medical websites. Any questions or comments about any of the definitions, terms or abbreviations included in this document should be directed to the author by email. Updated terms 2002, under the direction of  Philip E. Putnam, M.D., F.A.A.P. Updated terms 2013, under the direction of Seema Aceves, M.D., Ph.D.