Mesenteric venous thrombosis is a rare disease with no specific signs. It's major risk is intestinal ischaemia and necrosis. We report the case of a young women who presented with unexplained abdominal pain and subnormal abdominal ultrasound. The diagnosis was made on laparoscopic exploration which allowed anticoagulant therapy followed by proximal and distal divertingostomies of the ischemic bowel. Small bowel continuity was re-established after 3 month of total parenteral nutrition. The patients is doing well 1 year after surgery. She is still under anticoagulant therapy. The etiology found was a hypermegacaryocytosis as seen in myeloproliferative disease.