[Spontaneous rectal hematoma].

Five cases of spontaneous rectus sheath haematomas observed during one year are reported. The female to male ratio was four to one. The age range was 26-75 years. Precipitating factors were cough in three patients, physical exercise in one patient, and none in one patient. In three cases there were possible predisposing factors: anticoagulant therapy, Addison's disease with steroid treatment and abdominal scar. The localisations were three lower right quadrant, one lower left and one upper right. In three cases correct diagnoses were made based on clinical findings, confirmed by ultrasonography and treated conservatively. In two cases the diagnosis was not suspected clinically, and by ultrasonography the haematoma was overlooked in one case, and misinterpreted as an intraperitoneal tumour in the other; both cases underwent surgery. The incidence rate was estimated to 3.5 per 100,000 per year. The frequency was approximately 0.9% in patients admitted with "acute abdomen".