Gallstone Ileus

This patient presented with a small bowel obstruction. Note the gas in the biliary tree, and rounded opacity in the pelvis. Fortunately the patient had had an abdominal film 3 months previously which showed the same rounded calcific opacity in the right upper quadrant. A confident diagnosis of gallstone ileus could therefore be made on plain films alone.
Gallstone ileus is an uncommon cause of a small bowel obstruction. It occurs when a gallstone passes into the intestine and usually impacts at the iliocaecal valve. Usually passage into small bowel is by erosion from the gallbladder into the duodenum.
Rigler’s triad of findings: small bowel obstruction; pneumobilia; and gallstone in right iliac fossa.
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Reference: ACR Case in Point
Credit: Dr Frank Gaillard
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