Abdomen: The belly, that part of the body that contains all of the structures between the chest and the pelvis. The abdomen is separated anatomically from the chest by the diaphragm, the powerful muscle spanning the body cavity below the lungs.

Abdominal: Relating to the abdomen, the belly, that part of the body that contains all of the structures between the chest and the pelvis. The abdomen is separated anatomically from the chest by the diaphragm, the powerful muscle spanning the body cavity below the lungs.

Abdominal pain: Pain in the belly (the abdomen). Abdominal pain can come from conditions affecting a variety of organs. The abdomen is an anatomical area that is bounded by the lower margin of the ribs above, the pelvic bone (pubic ramus) below, and the flanks on each side. Although abdominal pain can arise from the tissues of the abdominal wall that surround the abdominal cavity (the skin and abdominal wall muscles), the term abdominal pain generally is used to describe pain originating from organs within the abdominal cavity (from beneath the skin and muscles). These organs include the stomach, small intestine, colon, liver, gallbladder, and pancreas.

Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).

Analysis: A psychology term for processes used to gain understanding of complex emotional or behavioral issues.

Antegrade: Forward-moving. As in blood flow. Sometimes synonymous with anterograde. From the Latin ante- + gradior, to step.

Anus: The opening of the rectum to the outside of the body.

Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis. (see osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, lupus, gout, pseudogout).

Bacteria: Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life).

Barium: A metallic element belonging to the alkaline earths with an atomic number of 56 and an atomic weight of 137.34. The symbol for barium is Ba. In medicine, refers to a chalky solution of barium used to coat the inside of organs so that they will show up on an x-ray.

Barium enema: A series of x-rays of the lower intestine (colon) and rectum that are taken after the patient is given an enema with a white, chalky solution that contains barium. The barium outlines the intestines on the x-rays. These x-rays permit the detection of colon and rectal abnormalities including diverticulosis, diverticulitis, abnormal colon movement, dilation (widening) of the colon, polyps and cancers of the colon and rectum.

Benign: Not cancer. Not malignant. A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place).

Biopsy: The removal of a sample of tissue for purposes of diagnosis. (Many definitions of "biopsy" stipulate that the sample of tissue is removed for examination under a microscope. This may or may not be the case. The diagnosis may be achieved by other means such as by analysis of chromosomes or genes.)

Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".

Bowel: Another name for the intestine. The small bowel and the large bowel are the small intestine and large intestine, respectively.

Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread).

Cecum: The cecum (also spelled caecum), the first portion of the large bowel, situated in the lower right quadrant of the abdomen.

Chills: Feelings of coldness accompanied by shivering. Chills may develop after exposure to a cold environment or may accompany a fever.

Colitis: Inflammation of the large intestine (the colon). There are many forms of colitis, including ulcerative colitis, Crohn's disease, infectious, pseudomembranous, and spastic. For example, intermittent rectal bleeding, crampy abdominal pain and diarrhea can be symptoms of ulcerative colitis. Diagnosis can be made by barium enema, but direct visualization (sigmoidoscopy or colonoscopy) is the most accurate test. Long-standing ulcerative colitis increases the risk for colon cancer. Ulcerative colitis can also be associated with inflammation in joints, spine, skin, eyes, the liver and its bile ducts. Treatment of ulcerative colitis can involve medications and surgery.

Colitis: Inflammation of the large intestine (the colon). There are many forms of colitis, including ulcerative colitis, Crohn's disease, infectious, pseudomembranous, and spastic. For example, intermittent rectal bleeding, crampy abdominal pain and diarrhea can be symptoms of ulcerative colitis. Diagnosis can be made by barium enema, but direct visualization (sigmoidoscopy or colonoscopy) is the most accurate test. Long-standing ulcerative colitis increases the risk for colon cancer. Ulcerative colitis can also be associated with inflammation in joints, spine, skin, eyes, the liver and its bile ducts. Treatment of ulcerative colitis can involve medications and surgery.

Colon: The part of the large intestine that runs from the cecum to the rectum as a long hollow tube that serves to remove water from digested food and let the remaining material, solid waste called stool, move through it to the rectum and leave the body through the anus.

Colon cancer: A malignancy that arises from the inner lining of the colon. Most, if not all, of these cancers develop from colonic polyps. Removal of these precancerous polyps can prevent colon cancer.

Colonoscope: A flexible, lighted instrument used to view the inside of the colon.

Colonoscopy: A procedure in which a long flexible viewing tube (a colonoscope) is threaded up through the rectum for the purpose of inspecting the entire colon and rectum and, if there is an abnormality, taking a biopsy of it or removing it. The colonoscopy procedure requires a thorough bowel cleansing to assure a clear view of the lining. Called also coloscopy.

Colorectal: Related to the colon and/or rectum.

Colorectal cancer: Cancer of the colon and rectum. A malignant tumor arising from the inner wall of the large intestine. Risk factors include heredity, colon polyps, and long standing ulcerative colitis. Most colorectal cancers develop from polyps. Removal of colon polyps can prevent colorectal cancer. Since colon polyps and early cancer can have no symptoms, regular screening is important. Diagnosis can be made by barium enema or by colonoscopy with biopsy confirmation of cancer tissue. Surgery is the most common treatment for colorectal cancer.

Complication: In medicine, an additional problem that arises following a procedure, treatment or illness and is secondary to it. A complication complicates the situation.

Computerized tomography: Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures.

Diarrhea: A familiar phenomenon with unusually frequent or unusually liquid bowel movements, excessive watery evacuations of fecal material. The opposite of constipation. The word "diarrhea" with its odd spelling is a near steal from the Greek "diarrhoia" meaning "a flowing through." Plato and Aristotle may have had diarrhoia while today we have diarrhea. There are myriad infectious and noninfectious causes of diarrhea.

Endoscopy: Endoscopy is a broad term used to described examining the inside of the body using a lighted, flexible instrument called an endoscope. In general, an endoscope is introduced into the body through a natural opening like the mouth or anus. Although endoscopy can include examination of other organs, the most common endoscopic procedures evaluate the esophagus (swallowing tube), stomach, and portions of the intestine.

Enema: Liquid injected into the rectum. An enema may be used for therapeutic (such as to stimulate evacuation of the bowels) or diagnostic (such as imaging studies of the gastrointestinal tract - barium enema) purposes.

Family history: The family structure and relationships within the family, including information about diseases in family members.

Fever: Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.).

Forceps: An instrument with two blades and a handle used for handling, grasping, or compressing. Many types of forceps are employed in medicine, including the alligator forceps (an angled instrument with jaws at the end), tissue forceps (a form of tweezer), hemostatic forceps (also simply called a hemostat, to clamp a bleeding vessel), mosquito forceps (a small hemostat) and obstetrical forceps (to aid in delivering a baby).

Gastroenterologist: A physician who specializes in the diagnosis and treatment of disorders of the gastrointestinal tract, including the esophagus, stomach, small intestine, large intestine, pancreas, liver, gallbladder, and biliary system.

Gastroenterology: The medical specialty devoted to the study, diagnosis and treatment of disorders of the digestive system. These disorders may affect the esophagus (swallowing tube), stomach, small intestine, large intestine (colon), rectum, liver, gallbladder, or pancreas.

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.

Ileum: The lowest part of the small intestine, located beyond the duodenum and jejunum, just before the large intestine (the colon). Pronounced "il-eum" in the US and "eye-leum" in the UK.

Incidence: The frequency with which something, such as a disease, appears in a particular population or area. In disease epidemiology, the incidence is the number of newly diagnosed cases during a specific time period. The incidence is distinct from the prevalence which refers to the number of cases alive on a certain date.

Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.

Insulin: A natural hormone made by the pancreas that controls the level of the sugar glucose in the blood. Insulin permits cells to use glucose for energy. Cells cannot utilize glucose without insulin.

Internal medicine: A medical specialty dedicated to the diagnosis and medical treatment of adults. A physician who specializes in internal medicine is referred to as an internist. A minimum of seven years of medical school and postgraduate training are focused on learning the prevention, diagnosis, and treatment of diseases of adults. Subspecialties of internal medicine include allergy and immunology, cardiology (heart), endocrinology (hormone disorders), hematology (blood disorders), infectious diseases, gastroenterology (diseases of the gut), nephrology (kidney diseases), oncology (cancer), pulmonology (lung disorders), and rheumatology (arthritis and musculoskeletal disorders).

Intestine: The long, tubelike organ in the abdomen that completes the process of digestion. It consists of the small and large intestines.

Iron: An essential mineral. Iron is necessary for the transport of oxygen (via hemoglobin in red blood cells) and for oxidation by cells (via cytochrome). Deficiency of iron is a common cause of anemia. Food sources of iron include meat, poultry, eggs, vegetables and cereals (especially those fortified with iron). According to the National Academy of Sciences, the Recommended Dietary Allowances of iron are 15 milligrams per day for women and 10 milligrams per day for men. Iron overload can damage the heart, liver, gonads and other organs. Iron overload is a particular risk in people who may have certain genetic conditions (hemochromatosis) sometimes without knowing it and also in people receiving recurrent blood transfusions. Iron supplements meant for adults (such as pregnant women) are a major cause of poisoning in children.

Laboratory: A place for doing tests and research procedures and preparing chemicals, etc. Although "laboratory" looks very like the Latin "laboratorium" (a place to labor, a work place), the word "laboratory" came from the Latin "elaborare" (to work out, as a problem, and with great pains), as evidenced by the Old English spelling "elaboratory" designating "a place where learned effort was applied to the solution of scientific problems."

Large intestine: Comes after the small intestine. Large because it is wider than the small intestine.

Laser: A powerful beam of light that can produce intense heat when focused at close range. Lasers are used in medicine in microsurgery, cauterization, for diagnostic purposes, etc. For example, lasers are employed in microsurgery to cut tissue and remove tissue.

Lesion: Pronounced "lee-sion" with the emphasis on the "lee," a lesion can be almost any abnormality involving any tissue or organ due to any disease or any injury.

Liquid diet: The Liquid diet is the restriction of solid food intake, and replacement of solid food with liquids. In hospitals, liquid diets are prescribed by doctors for a number of reasons for patients who are unable to consume solid foods. Liquid diets may be prescribed following surgery or as a preparation for certain medical procedures. Additionally, some people have injuries or medical conditions that limit their ability to eat solid foods. Most prescribed liquid diets allow sports drinks, broth, tea, and coffee. Strained juices may also be permitted.

Malignant: 1. Tending to be severe and become progressively worse, as in malignant hypertension. 2. In regard to a tumor, having the properties of a malignancy that can invade and destroy nearby tissue and that may spread (metastasize) to other parts of the body.

Microscope: An optical instrument that augments the power of the eye to see small objects. The name microscope was coined by Johannes Faber (1574-1629) who in 1628 borrowed from the Greek to combined micro-, small with skopein, to view. Although the first microscopes were simple microscopes, most (if not all) optical microscopes today are compound microscopes.

Microscopic: So small it cannot be seen without the aid of microscope. As opposed to macroscopic (large enough to be seen with naked eye). A tiny tumor is microscopic while a big tumor is macroscopic.

Neoplastic: Pertaining to a neoplasm or neoplasia. See those terms for more information.

Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.

Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.

Pathologist: A doctor who identifies diseases by studying cells and tissues under a microscope.

Pathology: The study of disease. Pathology has been defined as "that branch of medicine which treats of the essential nature of disease." The word "pathology" comes from the Greek words "pathos" meaning "disease" and "logos" meaning "a treatise" = a treatise of disease. The word "pathology" is sometimes misused to mean disease as, for example, "he didn't find any pathology" (meaning he found no evidence of disease). A medical doctor that specializes in pathology is called a pathologist. Pathologists are experts at interpreting microscopic views of body tissues.

Premalignant: Pertaining to tissue that is not yet malignant, but is poised to become malignant. Appropriate clinical and laboratory studies are designed to detect premalignant tissue while it is still in a premalignant stages. A large battery of techniques are generally available to remove or kill the tissue, thereby preventing the development of cancer. The proper treatment method depends on the particular premalignant tissue involved. Following are a few examples of premalignant growths:

Rectal bleeding: Blood passed rectally. Blood in the stool can be bright red or maroon in color. Larger amounts of blood that remain in the intestine long enough can turn the stool black. Blood in the stool also may be invisible to the naked eye (occult).

Rectum: The last 6 to 8 inches of the large intestine. The rectum stores solid waste until it leaves the body through the anus. The word rectum comes from the Latin rectus meaning straight (which the human rectum is not).

Residual: Something left behind. With residual disease, the disease has not been eradicated.

Resolution: In genetics, resolution refers to the degree of molecular detail on a physical map of DNA, ranging from low to high.

Scan: As a noun, the data or image obtained from the examination of organs or regions of the body by gathering information with a sensing device.

Sigmoidoscopy: Inspection of the rectum and lower colon using a thin lighted tube called a sigmoidoscope. Samples of tissue or cells may be collected for examination under a microscope. Also called proctosigmoidoscopy.

Small intestine: The part of the digestive tract that extends from the stomach to the large intestine.

Stool: The solid matter discharged in a bowel movement.

Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office.

Tear: A drop of the salty secretion of the lacrimal glands which serves to moisten the conjunctiva and cornea.

Tomography: The process for generating a tomogram, a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process.

Ulcerative colitis: A relatively common disease that causes inflammation of the large intestine (the colon). The cause is unknown.

Vein: A blood vessel that carries blood low in oxygen content from the body back to the heart. The deoxygenated form of hemoglobin (deoxyhemoglobin) in venous blood makes it appear dark. Veins are part of the afferent wing of the circulatory system which returns blood to the heart.

Virtual colonoscopy: A method for examining the colon by taking a series of x-rays and then using a computer to reconstruct three-dimensional pictures (a CT scan) of the interior surfaces of the colon from these x-rays. The pictures can be saved, manipulated to better viewing angles, and reviewed after the procedure. The procedure requires a 48-hour low-fiber diet and a complete bowel cleansing. If something suspicious is noted, a regular colonoscopy is needed to biopsy or remove it. Virtual colonoscopy results in about 15% false positives (misleading readings that unnecessarily require a regular colonoscopy). It is also not yet known whether virtual colonoscopy can reliably detect flat adenomas which, like polyps, can give rise to colon cancer. Also called computed tomography or CT colography.

Viruses: Small living particles that can infect cells and change how the cells function. Infection with a virus can cause a person to develop symptoms. The disease and symptoms that are caused depend on the type of virus and the type of cells that are infected.

Warfarin: An anticoagulant drug (brand names: Coumarin, Panwarfin, Sofarin) taken to prevent the blood from clotting and to treat blood clots and overly thick blood. Warfarin is also used to reduce the risk of clots causing strokes or heart attacks.

X-ray: 1. High-energy radiation with waves shorter than those of visible light. X-rays possess the properties of penetrating most substances (to varying extents), of acting on a photographic film or plate (permitting radiography), and of causing a fluorescent screen to give off light (permitting fluoroscopy). In low doses X-rays are used for making images that help to diagnose disease, and in high doses to treat cancer. Formerly called a Roentgen ray. 2. An image obtained by means of X-rays.