The unusual presentation of "large" gallstones. The diagnostic role of endoscopy.

Large gallstones are usually seen in old people, but are distinctly uncommon. They may cause complicated gallbladder disease requiring extensive surgery. Unusual presentations of such stones include Mirizzi's syndrome, biliary fistulas, and gastric outlet obstruction (Bouveret's syndrome). Preoperative endoscopy can accurately define these complications to facilitate their surgical management.