Inflammatory bowel disease (IBD)

It is estimated that around one in twelve people with AS (8%) also have inflammatory bowel disease (IBD).

Researchers have found that both AS and IBD have genes in common. IL23R is a gene that encodes a molecular switch involved in the healthy maintenance of a type of immune cell known as a Th17 lymphocyte. These are involved in inflammatory responses, particularly in mucosal surfaces like the gut. IL23R is associated with both AS and IBD.

There are two types of IBD: Crohn's disease and ulcerative colitis.

Crohn's disease

Crohn's disease is a chronic (long-term) condition that causes inflammation of the lining of the digestive system. Inflammation usually occurs in the the last section of the small intestine (the ileum), or the large intestine (colon). However, inflammation can occur anywhere in the digestive system, from the mouth to the back passage (anus).

Over time, the inflammation that is caused by Crohn's disease can damage sections of the digestive system, causing additional complications, such as narrowing of the colon.

Common symptoms of Crohn's disease include:

  • diarrhoea
  • abdominal pain
  • fatigue

The outlook for Crohn's disease is highly variable. People can have long periods of remission that last for weeks or months where they have no symptoms or very mild symptoms, followed by periods where their symptoms flare-up and are particularly troublesome.

There is currently no cure for Crohn's disease. However, medication is available that can be used to treat the symptoms and prevent them from returning.

About 80% of people with Crohn's disease will require surgery in order to relieve their symptoms, repair damage to their digestive system, and treat any associated complications of the condition.

Ulcerative colitis

Ulcerative colitis is a long-term (chronic) condition affecting the colon. Ulcerative colitis causes the large intestine (colon) to become inflamed and in severe cases, painful sores (ulcers) may form on the lining of the colon. These ulcers can bleed and produce mucus and pus.

Symptoms of ulcerative colitis include:

  • bloody diarrhoea
  • abdominal pain
  • a frequent need to go to the toilet
  • weight loss

Symptoms of ulcerative colitis can range from mild to severe, with the condition being very unpredictable. Symptoms can flare up and then disappear (go into remission) for months or even years.

The outlook for most people with ulcerative colitis is usually quite good. Symptoms are often mild to moderate and can usually be controlled using medication. However, an estimated one in five people with ulcerative colitis have severe symptoms that often respond less well to medication. In these cases, surgery may be necessary.

If you would like more information on IBD please contact Crohn's and Colitis UK. You can find their website at www.nacc.org.uk.

There was an interesting Westminster Hall debate on 13 January 2012 on employment and IBD which you can listen to here.

 Last reviewed: February 2012