Crohn's disease is classified as a disorder of inflammation . The body acts as though there were an infection or injury of the GI tract. The affected areas become red, swollen, and painful. They can bleed. Affected areas no longer perform their normal functions, so diarrhea sometimes results.
Ulcerative colitis affects only the colon, and has a different pattern of inflammation.
We will concentrate on Crohn's disease in this article, but will sometimes contrast it with ulcerative colitis. Scientists have found similarities between Crohn's disease and other diseases of the immune system. These include psoriasis and multiple sclerosis . Both Crohn's disease and ulcerative colitis can run in families. Sometimes both disorders are found in the same family.