Intestinal obstruction due to gallstones is a relatively rare condition. In 1890, Courvoisier1 reported 131 cases, and in 1917 Wagner2 found reports of 333 cases in the literature. Since that time numerous isolated instances and small series have been reported. During the past ten years, 10 cases have been observed at the University Hospital, constituting 5.3 per cent of all cases of intestinal obstruction.
A large gallstone may enter the lumen of the gastrointestinal tract through the common bile duct or through a fistula between the gallbladder and the bowel. The latter route is the more common. Such fistulas form at the site of inflammatory adherence of an adjacent viscus, usually the duodenum, to the gallbladder. Associated pressure of the gallstone causes necrosis and erosion of the gallbladder and the intestinal walls. Expulsion of the stone into the gastrointestinal tract may occur at the time of formation of