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Autoimmune condition



This results in swelling and redness (inflammation) of body tissue in the infected area.

In ulcerative colitis, a leading theory is that the immune system mistakes "friendly bacteria" in the colon, which aid digestion, as a harmful infection, leading to the colon and rectum becoming inflamed.

Alternatively, some researchers believe a viral or bacterial infection triggers the immune system, but for some reason it does not "turn off" once the infection has passed and continues to cause inflammation.




Studies have found more than 1 in 4 people with ulcerative colitis has a family history of the condition.


Researchers have identified several genes that seem to make people more likely to develop ulcerative colitis.

It's believed many of these genes play a role in the immune system.

Environmental factors


For example, the condition is more common in urban areas of northern parts of western Europe and America.


