Digestive involvement is frequent during the course of systemic small and medium-sized vessel vasculitides. Clinical manifestations range from rapidly regressive abdominal pain to surgical manifestations associated with poor prognosis. These are usually associated with extra-abdominal signs, reflecting vasculitis activity. Isolated gastrointestinal involvement is observed in only 16% of these patients. The main clinical manifestations are common to all vasculitides (ischemia, bowel infarction and perforations, gastrointestinal hemorrhage due to mucosal ulcerations or aneurysmal ruptures), but some are more specific to one type (granulomatous ileo-colitis during Wegener's granulomatosis, eosinophilic colitis during Churg-Strauss syndrome). Gastrointestinal arteriography can be helpful for diagnosis, but has no prognostic value, likewise for the presence of ANCA. As there are no identified factors predictive of a surgical abdomen, therapy must be adapted individually, using steroids and immunosuppressive agents, generally cyclophosphamide. Prompt surgical and medical care of these seriously ill patients has lowered mortality from nearly 100% twenty years ago to approximately 23 to 56% currently.