Chronic nonischemic disturbance of mesenteric venous blood flow is reported in 11 patients with a mean age of 19 years. This entity, rarely discussed in the literature, is different from acute thrombosis and chronic thrombotic forms with portal hypertension or hypercoagulopathy. In eight patients this syndrome was secondary to organic lesions of different origin: mesenteric vein squeezed by fibrous bands or an abnormal jejunal artery (four cases), lymphoma involving the distal superior mesenteric veins (three cases), hemangioma causing microthrombi (one case). In three patients no etiology or predisposing factor was found. All patients presented with rectal hemorrhage. Small bowel enema showed a constant pattern in 11 patients: small nodules, modified by compression or peristalsis, involving the mesenteric border of the jejunoileal segment, and associated with thick, straight but regular folds. Mesenteric varices were suspected and led to angiographic studies which were normal in three cases, confirmed varices in eight cases, and thrombosis in four cases. Laparotomy was normal in three cases and established the etiological diagnosis in eight cases. Varices were shown in six cases. Arteriography and laparotomy were unable to reach a complete diagnosis.