The exact cause of inflammatory bowel diseases (IBD) remains unknown. It is probable that these diseases are not due to a single cause. Instead, the inflammation that characterises these disease entities is triggered by a combination of different factors. For example, heredity appears to play a key role. Although neither ulcerative colitis (UC) nor Crohn’s disease represents an inherited disease in the usual sense, it does appear that a person’s genes are responsible for a certain susceptibility (“genetic predisposition”).
Many risk factors have been discussed, including infections, special dietary habits and disorders of the immune system, including over reactive immune responses.