Medical Terms

Glossary of IBD terms




Fibrous bands of scar tissue that may form following surgery. May lead to narrowing of the bowel. See also: stenosis

A condition where levels of red blood cells and haemoglobin are lower than normal, which reduces the amount of oxygen transported around the body. Iron deficiency anaemia (IDA) is the most common type of anaemia amongst people with IBD but is usually very easily treated under medical supervision. See also: iron deficiency anaemia

Anti-spasmodic drug

A drug that suppresses muscle spasms. See also: spasm

Autoimmune Disease

Any of a large group of diseases, including Crohn’s disease and ulcerative colitis, where the immune system inappropriately produces antibodies against your own tissues. Other commonly known autoimmune diseases include coeliac disease, type 1 diabetes, and rheumatoid arthritis.


Barium enema

An x-ray procedure used to examine the colon (large intestine). Barium sulfate is introduced via the rectum and is allowed to coat the colon. X-ray pictures are taken which will show if there are structural or motility abnormalities in the colon. See also: barium sulfate

Barium meal and follow through

An x-ray procedure used to examine the oesophagus (gullet), stomach and small intestine. The patient drinks liquid barium sulfate, which initially coats the oesophagus and stomach. X-ray pictures are taken as the patient swallows the barium to show if there are any structural or motility abnormalities. The patient is then asked to return to the x-ray room a few more times to capture images of the barium as it moves through the small intestine until it reaches the beginning of the large bowel. See also: barium sulfate

Barium sulfate

A compound which shows clearly on x-rays (radiopaque), and in liquid form is used to coat the gastrointestinal tract for the purpose of showing structural and motility abnormalities in the gut. See also: barium enema, barium meal and follow through

Biologic therapies

The most recent class of drug therapy to be used in IBD, these are genetically engineered medications made from living organisms and their products. The two main biologic therapies for IBD are Infliximab and Humira. Infliximab (or Remicade) is administered by intravenous (IV) infusion, usually every eight weeks (this can vary from patient to patient). Humira (or Adalimumab) is administered by the patient (or family member) every other week by subcutaneous injection.


A small sample of tissue or liquid taken from the living body to be examined to determine either the existence or cause of a disease. Biopsies are often taken during endoscopic examinations of patients with, or displaying symptoms associated with Crohn’s disease/ulcerative colitis. See also: endoscopy


See: intestine

Bowel obstruction

See: stenosis


Chronic disease

A disease that is ongoing and may last for many years, sometimes without a cure. Crohn’s disease and ulcerative colitis are examples of idiopathic (of no known cause) chronic diseases. The opposite of chronic disease is ‘acute’ or ‘self-limiting’ disease which is of short duration.


The surgical removal of some (or all) of the colon (the large intestine). A total colectomy is where the entire colon is removed. A proctocolectomy involves the removal of the colon and rectum. This is sometimes performed if ulcerative colitis or Crohn’s disease (affecting the colon) does not respond to medical treatment, to restore quality of life for the patient. In the case of ulcerative colitis, where the entire colon is removed (total colectomy) it is considered a cure for the disease as there is no colon left that can be affected by the disease. In the case of Crohn’s disease that affects the colon, it is possible for the disease to return to another part of the gastrointestinal tract, such as the small intestine. See also: colostomy


Inflammation of the colon. See also: enteritis, ileitis, microscopic colitis, ulcerative colitis


The large intestine (large bowel). It continues on from the small intestine. It consists of the caecum, the ascending colon, the transverse colon, the descending colon, the sigmoid colon leading on to the rectum and anus. It is approximately 1.5 metres long and its function is to absorb water and salt from the waste matter before emptying of the bowels. See also: intestine, small intestine


The examination of the large intestine (colon) and last part of the small intestine by passing a flexible tube with a light and camera (endoscope) through the anus. A very common examination performed in patients with, or displaying symptoms associated with Crohn’s disease/ulcerative colitis. See also: endoscopy


A surgical procedure involving joining a section of the colon (the large intestine) to an opening in the abdominal wall. This opening is known as a stoma. A pouch is placed over the stoma which collects waste matter that would normally pass through the colon and out of the body through the anus during a normal bowel movement. See also: stoma


Infrequent or difficult bowel movement often associated with hard stools.

Continent ileostomy

An ileostomy where the contents of the small intestine stay within the body until the patient decides to empty it. Waste matter drains into a surgically created pouch internally, rather than into an external pouch over the stoma. This is then emptied by inserting a catheter into a valve at the stoma site. See also: ileostomy, stoma

Corticosteroid (cortisone)

Often simply called ‘steroids’ these are one of a group of anti-inflammatory drugs prescribed to treat an acute flare-up of Crohn’s disease or ulcerative colitis. They can be given in tablet form, by enema, suppository, foam preparations, and intravenously in hospital. Owing to their side effects, it is not possible to take steroids indefinitely. A common form of corticosteroid administered for IBD is prednisolone.


See: spasm

Crohn's colitis

Crohn’s Disease involving the colon (the large intestine) and may be difficult to distinguish from ulcerative colitis. See also: crohn’s disease, indeterminate colitis

Crohn's disease

An inflammatory bowel disease. A chronic disease that causes inflammation of the lining of the digestive system anywhere from the mouth to anus. The most common site of inflammation is the small intestine. Causes a variety of symptoms and complications, which differ greatly from person to person. Most common symptoms are diarrhoea, abdominal pain, and fatigue. See also: chronic disease, crohn's colitis, diarrhoea, fatigue

CT (computed tomography)/CAT (computed axial tomography) SCAN

A medical imaging procedure that uses X-rays to produce cross-sectional images of the body.



This results when you are using or losing more water than you are taking in. In the case of people with Crohn’s disease and ulcerative colitis, this is commonly caused by diarrhoea. This upsets the balance of minerals in your body and can cause you to feel lightheaded. Can be treated with oral rehydration therapy. See also: diarrhoea, oral rehydration therapy


Bowel movements (or stools) that are loose and watery. A significant amount of water can be lost with each bowel movement which can result in dehydration. Can be treated with over-the-counter medication but prolonged diarrhoea should be investigated and treated under medical supervision. See also: dehydration, oral rehydration therapy, steatorrhoea


A healthcare professional who is trained in the field of diet and nutrition. Dietary management of IBD involves optimising nutrient intake to avoid malnutrition and unwanted weight loss, as well as modification of diet, which can enhance relief of some symptoms.


Bloating and swelling in the abdomen caused by wind and fluid in the intestines.


See: intravenous infusion


Elemental diet

A diet given wholly in liquid form used mainly in the treatment of Crohn’s disease to ensure adequate intake of calories and nutrients and to rest the bowel. Protein is broken down into its smallest parts called amino acids. This gives the patient’s diseased digestive system less work to do and aids absorption. It is sometimes used in the management of the disease in children to prevent growth and developmental problems.


The examination of the gastrointestinal tract by inserting a flexible tube with a  light and camera (endoscope) into the mouth or anus. See also: colonoscopy, gastroscopy, sigmoidoscopy


The process of introducing a liquid into the rectum and colon via the anus. 


Inflammation of the small intestine. See also: colitis, ileitis



Stools or bowel motions. Waste matter passed via the anus.


One of the more common symptoms of Crohn’s disease and ulcerative colitis. Can be caused by the disease process itself or iron deficiency anaemia. See also: iron deficiency anaemia


A split or crack in the skin around the anus sometimes seen in Crohn's disease patients.


An abnormal short circuit or false connection between two loops of intestine. They are more often observed in Crohn's disease than ulcerative colitis patients. There are several methods of healing these under medical supervision.

Flare up

The recurrence of IBD symptoms after a period of remission.

Folic acid

A vitamin which is responsible for the maintenance of red blood cells. IBD patients may be deficient but can take an oral supplement. See also: iron deficiency anaemia, vitamin B12



A physician specially trained to diagnose and treat disorders of the intestine to include Crohn's disease and ulcerative colitis.


The examination of the gastrointestinal tract as far as the stomach and duodenum by passing a flexible tube with a light and camera (endoscope) through the mouth. See also: endoscopy



Swollen, painful, dilated veins in the rectum and anus which may bleed. Usually treated successfully under medical supervision.


Examination of the microscopic structure of tissues.


A corticosteroid drug administered intravenously or as a foam enema preparation, which reduces inflammation.



Inflammation of the ileum, a portion of the small intestine. Regional Ileitis is used to describe Crohn's disease where the ileum is involved. See also: colitis, enteritis

Ileoanal anastomosis
Surgery performed in severe ulcerative colitis, whereby the colon is removed but the rectum and anus are retained. An internal pouch is formed using 2 or 3 loops of small intestine, which is then attached to the anus, thus preserving continence and allowing stools to be passed in the normal manner. This procedure is called a J pouch or Parks operation. See also: pouch


A surgical operation which is performed after a colectomy whereby the ileum is brought out and through the abdominal wall to form a stoma. An appliance bag is fitted to the skin around the stoma to collect waste matter. See also: continent ileostomy, stoma


One of the categories of drugs used to treat IBD. These drugs suppress the immune system with the aim of decreasing the inflammatory response. Also known as immunosuppressive drugs.

Indeterminate colitis

Where there is uncertainty as to the diagnosis of ulcerative colitis or Crohn’s disease in the colon.

Inflammatory bowel disease (IBD)

A group of inflammatory conditions that affect the colon and/or small intestine. Crohn’s disease and ulcerative colitis are the major diseases in this group. See also: crohn’s disease, ulcerative colitis

Intestine (bowel)

The segment of the gastrointestinal tract that extends from the pyloric sphincter of the stomach (at the end of the stomach) to the anus. The intestine consists of the small intestine and large intestine. The small intestine consists of the duodenum, jejunum and ileum. The large bowel consists of the caecum, the ascending colon, the transverse colon, the descending colon, the sigmoid colon, the rectum and the anus. See also: colon, small intestine

Intravenous infusion

Also known as a ‘drip’ this is the infusion of a liquid directly into a vein.


Inflamed, red painful eyes sometimes (but rarely) experienced by Crohn's Disease and ulcerative colitis patients.

Iron deficiency anaemia (IDA)

The most common form of anaemia amongst people with IBD but is often under diagnosed. It is caused by a lack of iron in the body. Causes include loss of blood through bleeding and malabsorption of iron/Folic Acid/Vitamin B12. Low levels of iron can mean organs and tissues do not get as much oxygen as they need and this can lead to a range of symptoms such as tiredness, headache, shortness of breath, fast heartbeat, dizziness, poor concentration, reduced libido, and fainting. IDA can usually be treated very effectively under medical supervision. See also: anaemia, fatigue, folic acid, vitamin B12

Irritable bowel syndrome (IBS)

This is not to be mistaken for Inflammatory Bowel Disease, though some of the symptoms are similar. IBS, also known as spastic colon, is not characterized by inflammation, as is the case with IBD.


Lactose intolerance

The inability to digest lactose, a sugar found in milk and dairy products, where the enzyme lactase is either lowered or missing. Lactase enables lactose to be digested in the small intestine. Lactose intolerance is often observed in people with Crohn's disease during a flare up of the disease. Symptoms can be quite severe and include bloating, cramps, flatulence, diarrhoea, and vomiting. These can often be masked by the symptoms of Crohn’s disease itself. If affected, patients should replace milk and dairy products with lactose-free alternatives that do not compromise their nutritional intake. Lactose intolerance is usually only temporary in people with Crohn’s disease and the ability to digest milk and dairy products should resume when remission is achieved.

Large intestine

See: intestine


See: white blood cells


Microscopic colitis

A form of colitis where the lining of the colon appears normal (unlike ulcerative colitis where inflammation is observed). Microscopic colitis derives its name because it must be diagnosed under microscope. It is an idiopathic (of no known cause) disease which usually responds well to treatment.

MRI (magnetic resonance imaging) scan

A medical imaging technique which uses magnetic fields to produce cross-sectional images of the body in any plane.


The lining of the intestines, responsible for absorption and secretion.


Produced by the mucosal lining of the intestines. It is a slimy white substance and is found in the bowel movements of patients with ulcerative colitis.


Nasogastric tube

A thin flexible tube which is passed through the nose into the stomach. It can be used for feeding or administering drugs directly to the stomach. It can also be used for nasogastric aspiration (suction) whereby the contents of the stomach are drained via the tube. This is sometimes necessary in patients with gastrointestinal obstructions where the tube is used to remove gastric secretions and swallowed air.

NSAID (non steroidal anti inflammatory drug)

A classification of drug which do not contain steroids, used to reduce swelling and relieve pain. People with Crohn’s disease and ulcerative colitis should only take these drugs under medical advice, as they are known to cause complications of these diseases. The most common form of over-the-counter NSAID is Ibuprofen.



A blockage of the small or large intestine most commonly observed in patients with Crohn's disease which is caused by a stricture (narrowing) of the intestine.

Occult blood

Blood in the stools which is not visible to the naked eye. It can be detected by a laboratory test.


Swelling due to the accumulation of fluid in the tissues.

Oesophagus (gullet)

The section of the gastrointestinal tract running from the throat to the stomach.

Oral rehydration therapy

Used to treat dehydration by replacing lost water and body salts, often caused by diarrhoea. A powder for making up rehydration solution is mixed with water and taken orally. Several over-the-counter rehydration products are available from pharmacies or on prescription. See also: dehydration, diarrhoea


Thinning of the bones due to the loss of calcium. In IBD this may be caused by long-term use of corticosteroids.


An artificial opening onto the abdominal wall of the intestine (colostomy/ileostomy) or the bladder (urostomy). The surgical formation is known as a stoma. See also: colostomy, ileostomy, stoma


Pan colitis

A severe form of ulcerative colitis involving the entire length of the colon. See also: ulcerative colitis

Parenteral nutrition

Providing nutrition via a vein. Total parental nutrition (TNP) involves providing all of the body’s nutrition in this manner. It is sometimes used in very severe cases of IBD and involves administering the body’s total nutrition via a vein near the neck. This ensures the nutrition is taken very quickly to the heart for distribution around the body.


An infectious agent (germ) which causes disease. Examples of pathogens include bacteria and viruses.


An abnormal opening in the bowel wall which allows bowel contents to escape or leak into another area of the abdomen. This will require immediate surgical intervention.


To describe the area around the anus or anal opening.


See: haemorhoids


A growth which protrudes from the mucosa (lining of the intestines). More common in the colon (large intestine) than in the small intestine).

Pouch (ileo-anal)

An internal reservoir or pouch which is surgically constructed using a few loops of small intestine at the ileum which is then attached to the anus thus preserving continence and allowing emptying of the bowels. See also: ileoanal anastomosis, pouchitis


Inflammation of the ileo-anal pouch caused by an overgrowth of bacteria. See also: ileoanal anastomosis, pouch


A corticosteroid drug used to reduce inflammation in Crohn's Disease and ulcerative colitis. See also: corticosteroid

Primary sclerosis cholangitis

One of the complications that can be associated with ulcerative colitis where there is inflammation of the bile ducts (the tubes that transport bile from the liver). Symptoms include itchy skin and tiredness.


A form of ulcerative colitis affecting the rectal and anal area. See also: ulcerative colitis


The total surgical removal of the colon and rectum.


A forecast of the likely course of a disease.



A specialist physician trained in reading x-rays and other imaging techniques, for the purpose of reaching a diagnosis.  


The final part of the colon where stools are stored prior to a bowel movement.

Red blood cells (erythrocytes)

The cells in the blood which carry oxygen from the lungs to the tissues.


A flare-up or return of disease activity after a period of remission or good health.


A reduction in the severity of the disease and its symptoms, and a return to good health.


The surgical removal of the diseased portion of the intestine, and the joining of the two healthy ends together.



The examination of the mucosa (lining) of the rectum and lower colon by passing a tube with a light and camera (endoscopy) through the anus. See also: endoscopy

Small intestine

Also known as the small bowel, this is the section of the gastrointestinal tract which extends from the stomach to the colon. The average length is around 7m. It consists of three parts. The upper section is called the duodenum. The middle section is called the jejunum. The lower section is called the ileum. This small intestine is where food is digested and nutrients are absorbed after it has passed through the stomach. Where Crohn’s disease affects the small intestine, this can result in malabsorption of essential nutrients causing nutritional deficiencies and/or weight loss.


A contraction of the smooth muscle, and can occur in the stomach and intestines of people with IBD. They can range in intensity and duration and cause varying degrees of pain and discomfort. The treatment for spasms include anti-spasmodic drugs. See also: anti-spasmodic drug


Excessive amounts of fat found in the stools due to poor absorption by the small intestine. Can often be identified where stools float or have an oily appearance. Often associated with active Crohn’s disease as a result of which patients are advised to adhere to a low-fat diet. See also: diarrhoea


A narrowing of any part of the intestine (bowel) below the duodenum. If severe it may lead to a bowel obstruction whereby the contents of the bowel cannot move normally through the bowel. This is a medical emergency requiring immediate medical attention.  


See: corticosteroid


An opening which connects a portion of the body cavity to the outside. A surgically constructed opening of the small intestine onto the surface of the abdominal skin and is known as an ileostomy. An opening from the colon in a similar fashion is called a colostomy. In both cases a disposable bag is fitted to the stoma to collect waste matter. See also: colostomy, ileostomy


Bowel motions or faeces.


See: stenosis


A surgical procedure performed to alleviate bowel narrowing due to scar tissue that has built up in the intestinal wall from inflammatory bowel conditions such as Crohn’s disease. The scar tissue accumulates as a result of repeated damage and healing, with the scarring causing a stricture (a narrowing of the lumen of the bowel).


A bullet-shaped drug in solid form which is inserted into the body via the anus and rectum.



A sudden and frequent urge to empty the bowels which is usually caused by inflammation of the rectum.

Terminal ileum

The final part of the small intestine before it joins the large intestine. A common part of the gastrointestinal tract to be affected by Crohn’s disease.

Toxic megacolon

A rare but serious complication of severe ulcerative colitis or Crohn’s colitis (Crohn’s disease affecting the colon). Severe inflammation can causes gases to get trapped in the colon causing it to swell. This condition requires immediate medical attention.   



An open sore observed on the skin or internal tissues of the body.

Ulcerative colitis

An inflammatory bowel disease. A chronic disease that causes inflammation of the lining of the colon (large intestine). Causes a variety of symptoms and complications which differ greatly from person to person. Most common symptoms are diarrhoea, abdominal pain, and fatigue. See also: chronic disease, crohn’s colitis, diarrhoea, fatigue, microscopic colitis, pan colitis, proctitis


A diagnostic imaging technique which is used to create images of body structures such as tendons, muscles and internal organs, for the purpose of helping diagnosis of injury or disease. It is usually carried out on the abdomen of IBD patients.


Sometimes (but rarely) seen as a complication of IBD affecting the eyes and causing redness and discomfort.