Internal Hernia
A protrusion of an internal abdominal organ through a hole in an anatomical structure such as a muscle or a membrane. For instance, in paraduodenal hernia the SMALL INTESTINE herniates through an opening in the MESENTERIES. It includes intra-abdominal and diaphragmatic hernias. In abdominal hernia a protrusion occurs through a weak spot in the muscle of the ABDOMINAL WALL.