[Portal vein thrombosis: a rare complication of Crohn disease].

Among usual extra digestive manifestations of inflammatory bowel diseases, vascular injuries are rare, but often of excessive gravity. The emergence of a portal thrombosis, often accelerated by infection or traumatism, particularly surgical, remains exceptional. We report the case of a young patient who is followed for a severe crohn's disease and affected with a brutal portal vein thrombosis. Although initial prognosis was bad, the patient now lead a normal life ten months after this episode. It's the third described case of portal thrombosis in crohn's disease. We discuss the predisposing role of an acquired protein S deficiency during a estroprogestative treatment.