RESUMEN
BACKGROUND: Congenital transmesenteric hernia in children is a rare and potentially fatal form of internal abdominal hernia, and no specific clinical symptoms can be observed preoperatively. Therefore, this condition is not widely known among clinicians, and it is easily misdiagnosed, resulting in disastrous effects. CASE SUMMARY: This report presents the case of a 13-year-old boy with a chief complaint of abdominal pain and vomiting and a history of duodenal ulcer. The patient was misdiagnosed with gastrointestinal bleeding and treated conservatively at first. Then, the patient's symptoms were aggravated and he presented in a shock-like state. Computed tomography revealed a suspected internal hernia, extensive small intestinal obstruction, and massive effusion in the abdominal and pelvic cavity. Intraoperative exploration found a small mesenteric defect approximately 3.5 cm in diameter near the ileocecal valve, and there was about 1.8 m of herniated small intestine that was treated by resection and anastomosis. The patient recovered well and was followed for more than 5 years without developing short bowel syndrome. CONCLUSION: In this report, we review the pathogenesis, presentation, diagnosis, and treatment of congenital transmesenteric hernia in children.