Extraintestinal manifestations of inflammatory bowel disease

Extraintestinal manifestations of Crohn's disease and ulcerative colitis are found in > 50% of all patients. These extraintestinal manifestations sometimes impair the overall life quality much more than the bowel-related symptoms. Extraintestinal manifestations need to be distinguished from secondary diseases or complications of inflammatory bowel diseases, as they require a different and specific therapy. Complications of the intestinal disease, such as vitamin deficiency or osteoporosis, can be treated specifically by substitution of vitamin D, calcium, or other vitamins. However, extraintestinal manifestations of Crohn's disease and ulcerative colitis, such as primary sclerosing cholangitis, arthritis or granulomatous inflammation of the skin, lung, or liver, are much more difficult to treat sufficiently. Almost every organ can be a localization of extraintestinal symptoms of inflammatory bowel diseases. It is important to acquire knowledge on these extraintestinal manifestations of Crohn's disease and ulcerative colitis to start the respective treatment early. Perhaps even more important, these extraintestinal symptoms can be the primary manifestation of Crohn's disease and ulcerative colitis. Therefore, they have to be recognized as extraintestinal manifestations to adequately treat the intestinal disease.