Inflammatory bowel diseases (IBD) are chronic disorders characterised by swollen and damaged tissues in the lining of the intestinal tract, these conditions vary in severity from patient to patient and change over time. During a flare-up a patient may experience frequent bouts of watery and sometimes bloody diarrhoea, abdominal pain, weight loss, and fever. Between these flare-ups symptoms frequently diminish. Many patients may go through extended periods of remission before another flare-up occurs.

The cause of IBD is not known, but these diseases are thought to be due to an autoimmune process that has been triggered by a genetic predisposition, a viral illness or an environmental factor. IBD affects both sexes equally and is seen most frequently in Caucasians who live in industrialised countries. The most common inflammatory bowel diseases are Crohn’s disease and ulcerative colitis.

Both diseases may affect anyone at any age, but the majority are first diagnosed in patients between 15 and 35 years of age (and a smaller number between the ages of 50 and 70). In addition to gastrointestinal symptoms, children affected by either disease may experience delayed development and growth retardation. Patients who are diagnosed with one of these conditions at a young age are also at an increased risk of developing colon cancer later in life.

Crohn’s disease can affect any part of the gastrointestinal tract from the mouth to the anus, but is most commonly found in the last part of the small intestine (the ileum) and the first part of the colon (large intestine or bowel). Bowel tissue may be affected in patches with normal tissue in between. Inflammation may penetrate deep into the tissues of the intestine and form ulcers or fistulae (tunnels through the intestinal wall into another part of the gut or another organ).

Other complications of Crohn’s disease may include bowel obstruction, anaemia from bleeding tissue, and infections. About 80% of patients with Crohn’s disease require surgery at some stage, either to remove damaged sections of the intestine or to treat an obstruction or fistula.

Ulcerative colitis primarily affects the surface lining of the colon. Although the symptoms may be similar to those seen with Crohn’s disease, the tissue inflammation is continuous and usually starts from the anus and moves up the colon. Ulcerative colitis tends to present more frequently with bloody diarrhoea. Its most serious complication is toxic megacolon, a relatively rare acute condition in which a section of the colon becomes paralysed. Faeces does not move through the section and it accumulates and dilates the colon. This can cause abdominal pain, fever, and weakness and can become life threatening if left untreated.