Presentation
Vomiting and abdominal distension. Clinical small bowel obstruction.
Patient Data
A circular calcified density is seen projected over the lower abdomen.
Distended loops of gas-filled small bowel consistent with small bowel obstruction. No evidence of perforation.
Features of small bowel obstruction with gas- and fluid-filled loops of bowel. Transition point in the midline of the pelvis with a large calcfified gallstone.
Biliary gas with gas in the gallbladder and a visible cholecystoduodenal fistula.
Case Discussion
Large gallstones cause gallbladder distension with opposition of the gallbladder and duodenal walls. When there is a long-standing irritation between the two, fistula can form. Once a small fistula forms, constant irritation from the gallstone causes its enlargement until the gallstone can escape.
Once the fistula has formed, gas can be demonstrated in the biliary tree and gallbladder.