Extra-intestinal manifestations of inflammatory bowel diseases.

Inflammatory bowel disease (IBDs), including the two main subtypes of Crohn's disease and ulcerative colitis, not only affects the gastrointestinal system, but also has a wide range of extra-intestinal manifestations (EIMs) that are major sources of morbidity and disability, and therefore represent what can be considered a real syndrome. The pathogenetic mechanisms underlying these EIMs are unknown, but some may share a common pathogenesis with IBD and others may be due to IBD treatment. The aim of this review is to examine our current knowledge of IBD EIMs and their treatment.