Crohn's disease

Chronic inflammatory bowel disease. It tends to flare up for a few days at a time, causing diarrhoea, abdominal cramps, loss of appetite, weight loss, and mild fever. The cause of Crohn's disease is unknown. However, research teams in Europe and the USA found that a number of cases of Crohn's disease can be attributed to a fault in the gene Nod2, which partly controls the way the immune system responds to gut microbes. Stress may also be a factor.

Crohn's disease may occur in any part of the digestive system but usually affects the small intestine. It is characterized by ulceration, abscess formation, small perforations, and the development of adhesions binding the loops of the small intestine. Affected segments of intestine may constrict, causing obstruction, or may perforate. It is treated by surgical removal of badly affected segments, and by corticosteroids. Mild cases respond to rest, bland diet, and drug treatment. Crohn's disease first occurs most often in adults aged 20–40.

In these cases ulceration is believed to be caused by the immune system attacking the healthy gut lining.