[Internal abdominal hernia. Unusual cause of intestinal occlusion].

Internal abdominal hernias are an unusual cause of intestinal occlusion. They are responsible for 2% of all the intestinal obstructions. Various types of hernia have been described. The diagnosis is difficult, but should be suspected in patients suffering from intestinal obstruction who have undergone earlier laparotomy. Diagnosis is even more difficult in cases of congenital internal hernia. The authors report a case of left paraduodenal hernia (congenital), and a case of transmesenteric hernia (acquired). Both patients complained of a short history of abdominal pain and characteristic symptoms of acute abdomen (nausea, vomit, cramps and obstipation). Emergency surgery using laparotomy enabled diagnosis and treatment. The authors underline the difficulty of diagnosing these hernias and emphasise the diagnostic and therapeutic importance of emergency surgery.