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NOTE: Some of the information provided contains graphic, medical images which individuals may find upsetting

Crohn’s disease causes inflammation in part of the gut, most commonly the lower part of the small bowel, called the ileum, but it can affect any part of the digestive tract from the mouth to the anus. The inflammation can cause pain and make the bowel empty frequently, resulting in diarrhoea.

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What causes Crohn’s disease?

Nobody is sure what causes Crohn’s disease. The most popular theory is that the body’s immune system reacts to a virus or bacterium by causing ongoing inflammation of the bowel.

What are the symptoms?

The most common symptoms are abdominal pain, often in the lower right abdomen, and diarrhoea. Rectal bleeding, weight loss and fever may also occur.

How is the diagnosis made?

After listening to you and doing a general examination your consultant will usually examine the rectum (back passage) with a finger. Investigations may include:

  • An inspection of the bowel with a telescope (sigmoidoscopy or colonoscopy)
  • A laboratory examination of your stool samples to see if there is infection or inflammation
  • Blood tests
  • A barium x-ray examination of your bowel
  • An MRI scan of your bowel

Crohn’s disease is often difficult to diagnose because its symptoms are similar to other bowel disorders such as irritable bowel syndrome or ulcerative colitis.

What is the treatment for Crohn’s disease?

This depends on the location and severity of disease, complications and response to previous treatment. The goals of treatment are to control inflammation, correct any nutritional deficiencies and relieve symptoms. Treatment may include drugs, nutrition supplements, surgery or a combination of these.


  • Steroids such as prednisolone are often prescribed for moderate to severe attacks of Crohn’s disease to damp down the inflammation. Steroids may be given as tablets by mouth, enemas, rectal foams or suppositories via the back passage. Severe attacks will be treated in hospital with steroids given via a vein into the blood stream.
  • Another drug, cyclosporin, is sometimes given with intravenous steroids.
  • Sulphasalazine, mesalazine or olsalazine are often given during an attack and for long-term use to keep the disease in remission. These drugs may be given as tablets, enemas or suppositories.
  • Azathioprine is used for a few patients with long term active disease who would otherwise need repeated courses of steroids.
  • Antibiotics may be used to treat bacterial proliferation in the small bowel caused by bowel narrowing. Diarrhoea may be controlled with drugs that slow the bowel down such as loperamide, or codeine.

Anti-TNF drugs are another group of drugs that can be given to try and prevent inflammation. These drugs are only used in a few patients with severe disease and are given by a Gastroeneterologist.

What problems can occur in Crohn’s?

The most common complication is blockage of the bowel. This occurs because the disease tends to thicken the bowel wall, narrowing the passage. The disease may also cause sores or ulcers that tunnel through the affected area into surrounding tissues such as the bladder or skin. These tunnels are called fistulas and may require an operation to correct.

Will I need an operation?

People with Crohn’s disease may feel well and be free of symptoms for long periods when their disease is not active. Many people with Crohn’s disease will require surgery at some point, either to relieve symptoms that do not respond to medical therapy or to correct complications such as blockage, fistulas, abscess or bleeding. Surgery to remove part of the intestine can sometimes help people with Crohn’s disease but cannot cure it. These operations can be done with single large incision (open surgery) or multiple small incisions (‘key-hole’ or laparoscopic surgery).  The inflammation tends to return next to the area of intestine removed. Your Consultant, General Practitioner and Specialist Nurse can give you more information if surgery is contemplated.

Is a stoma necessary?

A stoma (colostomy, ileostomy), or artificial opening of the colon/small bowel on to the abdominal wall is NOT always necessary in these operations but can be required either on a temporary or permanent basis. The possibility of requiring a stoma will be discussed with you and if it is required then you will get all the support that you need.

Further information