Extra intestinal manifestations and complications in inflammatory bowel disease.

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), doesn't affect only the intestinal tract, but also involve other organs such as: eyes, skin, joints, liver and biliary tracts, kidneys, lungs, vascular system. It is difficult to differentiate the true extraintestinal manifestations from secondary extraintestinal complications. The pathogenetic autoimmune mechanisms include genetic susceptibility, antigenic display of autoantigen, aberrant self-recognition and immunopathogenetic autoantibodies against organ-specific cellular antigens shared by colon and extra-colonic organs. An important role is owned by microbes due to molecular mimicry. This paper reviews the frequency, clinical presentation and therapeutic implications of extraintestinal symptoms in inflammatory bowel diseases.