Pneumobilia: a case report and literature review on its surgical approaches.

Gallstones ileus is an uncommon cause but important cause of small bowel obstruction. The gallstone enters the intestinal lumen via a fistula located in the duodenum (cholecystoduodenal), or rarely, in the colon (cholecystocolonic) or stomach (cholecystogastric). This may result in large bowel or gastric outlet obstruction (Bouveret's Syndrome).