Pediatric malrotation with concurrent transmesocolic hernia

Background: Intestinal malrotation and congenital transmesocolic internal hernia are rare congenital anomalies. Their simultaneous occurrence in a school-aged child is exceptionally rare and represents a critical surgical emergency due to the high risk of rapid closed-loop strangulation and bowel necrosis. Case presentation: A 6-year-old male presented with a 6-day history of intermittent abdominal pain, 3 days of vomiting, and 24 hours of obstipation. Despite progressive obstruction, his abdomen was flat and non-tender. Plain radiography showed mechanical small bowel obstruction with air-fluid levels, while ultrasonography was unremarkable. Emergency laparotomy revealed midgut malrotation with a left-sided cecum, Ladd’s bands compressing the duodenum, and three loops of proximal jejunum herniated through a 2 × 2 cm transverse mesocolic defect; the defect was located distal to the middle colic vessels and involved approximately 40 cm of jejunum. Following reduction, the bowel was fully viable. A complete Ladd’s procedure was performed, including division of Ladd’s bands, broadening of the mesenteric base, primary closure of the mesocolic defect, bowel repositioning, and appendectomy. The patient was discharged on postoperative day 7 and remained asymptomatic at a 1-month follow-up. Conclusion: The coexistence of malrotation and a transmesocolic internal hernia can cause severe bowel obstruction in an older child with a deceptive, flat, and non-tender abdomen. This clinical dissociation can dangerously delay surgical referral. In resource-constrained settings lacking computed tomography, clinical assessment and plain radiographic evidence of obstruction are sufficient grounds for emergency exploratory laparotomy. A complete Ladd’s procedure combined with defect closure ensures excellent outcomes without the need for bowel resection.