An infant autopsy case of bowel obstruction due to internal abdominal hernia.

Internal abdominal hernia, defined as protrusion of viscera through a defect of the mesentery, has been considered a rare clinical entity. Recent clinical reviews reported a wide range of onset age (from newborns to the elderly) and symptoms (from minimal abdominal symptoms to severe acute abdomen). Sudden and unexpected death due to internal abdominal hernia is rare in infants or toddlers, and only 4 autopsy cases had been reported previously. We report the case of a 3-month-old Japanese boy who unexpectedly died 4 h after first vomiting. Autopsy showed a wide bowel obstruction with necrosis through a congenital mesenteric defect. The larynx was filled with gastric content (milky white viscous muddy material). In the cross section of both lungs, the same material was found to be expressed from the bronchioles. We diagnosed the cause of death as asphyxiation by viscous milk/vomitus aspiration caused by bowel obstruction due to an internal abdominal hernia. In case of sudden and unexpected death of an infant, autopsy is crucial to determine the cause of death. During autopsy, it is helpful to determine the character and distribution of gastric and airway contents to confirm milk or vomitus aspiration.