Strangulated transomental hernia causing small bowel obstruction in a virgin abdomen

Transomental hernia is a rare cause of small bowel obstruction and may be missed before surgery, particularly in a virgin abdomen. We report a 75-year-old woman with no previous abdominal operation who presented with 4 days of abdominal pain, vomiting, distension, constipation, and reduced urine output. She had leukocytosis and acute kidney injury. Because of renal dysfunction, computed tomography was performed without intravenous contrast. It showed dilated ileal loops, a pelvic transition point, mild ascites, and twisting of mesenteric vessels at the transition point, suggestive of volvulus or closed-loop obstruction. Internal hernia was not diagnosed preoperatively. Emergency laparotomy revealed ileum strangulated through a 3 cm greater omental defect. Approximately 120 cm of gangrenous ileum was resected, the defect was excised, and single-layer extramucosal hand-sewn end-to-end anastomosis was performed. The case emphasizes that closed-loop obstruction in a virgin abdomen should prompt early consideration of internal hernia.