637 Enterolith Ileus Secondary to Small Bowel Diverticulum: A Rare Cause of Small Bowel Obstruction

Abstract Small intestinal diverticula are rare and possibly acquired secondary to bowel dyskinesia, abnormal peristalsis, or high intraluminal pressures. Enterolith formation and obstruction are a less encountered complication of these diverticula. An elderly man, with no history of abdominal surgery, presented with 10 days of colicky right iliac fossa pain and recurrent episodes of bilious vomiting. He initially reported diarrhoea but complained of eventual absolute constipation for last 5 days. Physical examination revealed distended abdomen with right-sided tenderness and no mass or faeces on rectal examination. Abdominal CT revealed a 3.5 cm calculus in the distal ileum causing obstruction initially flagged as gallstone ileus. No gallstones or pneumobilia were identified although some intrahepatic duct dilatation was noted. An emergency laparotomy was conducted, where the radiological findings were reinforced, and the calculus was extracted via enterotomy. There were no abnormal communications between gallbladder and intestinal tract. The small bowel traced from duodenojejunal flexure to terminal ileum did not reveal any further calculi or diverticula. FTIR spectrum analysis of the extracted specimen indicated similarities to enterolith. Retrospective analysis of radiological images revealed a possible duodenal diverticulum. The case highlights the diagnostic conundrum and therapeutic challenges of small bowel diverticular enterolith.