Transmesocolic Internal Herniation Presenting as Small Bowel Obstruction in a Virgin-Abdomen: A Diagnostic Challenge

Background: Transmesocolic hernias are a rare subtype of internal hernia and an uncommon cause of small bowel obstruction. Preoperative diagnosis remains challenging because of their nonspecific clinical and radiological presentation, particularly in surgery-naïve patients. Delayed recognition may result in bowel strangulation, ischemia, and significant mortality. We report a case of transmesocolic internal hernia presenting as acute intestinal obstruction in a patient without previous abdominal surgery. Case Presentation: A middle-aged gentleman presented with acute history which suggests intestinal obstruction. Contrast-enhanced computed tomography (CT) demonstrated dilated small bowel loops with twisting of the mesentery. An emergency exploratory laparotomy was performed. Intraoperatively, small bowel had herniated through a defect in the transverse mesocolon into the lesser sac. The herniated bowel loops appeared congested but remained viable. The postoperative recovery was uneventful, and the patient was discharged well. Conclusion: Transmesocolic hernia is a rare but important differential diagnosis in surgery-naive patients presenting with small bowel obstruction. Due to the difficulty in establishing a preoperative diagnosis, a high index of suspicion and prompt surgical intervention are essential to prevent bowel ischemia and improve patient outcomes.