Very early onset inflammatory bowel disease.

Very early onset inflammatory bowel disease (VEO-IBD) represents a unique and growing subset of patients with inflammatory bowel disease (IBD). Some VEO-IBD patients present with immunodeficiency and possess loss of function genetic mutations involving immune pathways that cause their IBD. A search for Mendelian causes of IBD is likely most beneficial when the presentation involves extra-intestinal autoimmunity or involves intestinal histopathology that is atypical for IBD. While a subset of these young patients will have highly aggressive courses (and likely present with immunodeficiency), the majority of patients with VEO-IBD appear to have disease courses similar to that of their older counterparts. Most notably, many of these young children will require long courses of immunosuppression simply as a result of the profoundly early presentation-thus increasing their long-term risks of cancer and opportunistic infections.