An unusual cause of small bowel obstruction.

A 95-year-old woman with a virgin abdomen presented to the Emergency Department (ED) with a 1 week history of vomiting, absolute constipation and generalised abdominal pain. Physical examination revealed tender abdominal distension with hyperactive bowel sounds and no hernias. Abdominal plain film radiograph (PFR) showed dilated small bowel loops without an obvious transition point or a radiologically apparent cause (Fig. 1a). Abdominal computed tomography scan (CT scan) revealed a cholecysto-duodenal fistula, pneumobilia and dilated small bowel loops proximal to a 1 cm diameter calcified intra-luminal structure in the distal ileum consistent with an ectopic gallstone (Fig. 1b, c). The patient underwent mini-laparotomy through a right iliac fossa incision, enterolithotomy and extraction of a 2.5 cm diameter gallstone (Fig. 1d), from which she recovered uneventfully.