aetiology
Last reviewed 01/2018
Gallstone ileus often develops as a complication of chronic cholecystitis. As the inflamed gallbladder becomes adherent to adjacent intestine, a stone may ulcerate through the gallbladder wall to form a cholecystenteric fistula. Most commonly, the fistula is located in the duodenum or colon; rarely it may be in the stomach or the jejunum. The fistula decompresses the obstructed gallbladder so permitting stones to pass through into the bowel and gas to pass into the biliary tree.
Gallstone ileus results when large stones, usually solitary and greater than 2.5 cm diameter, traverse the small bowel and impact in the narrow distal ileum.