The development of abdominal pain in the patient receiving anticoagulant therapy is more likely to pose a diagnostic dilemma. A group of intra-abdominal bleeding syndromes, which are extremely rare in patients with normal haemostasis, have been described in patients on anticoagulant therapy. Theses syndromes are of particular interest to surgeons because they simulate acute surgical conditions of the abdomen. We herein report the preoperative diagnosis of a spontaneous intramural hematoma of the small bowel by computed tomography. The authors conclude that CT should be used early in the diagnostic evaluation of abdominal pain and of acute abdomen in patients receiving anticoagulant therapy. Indications for the operative management of these patients include active bleeding, pneumoperitoneum, failure to improve with conservative management within 72 hours, worsening of symptoms, and uncertain diagnosis.