A Rare Presentation of a Transverse Mesocolic Internal Hernia: A Case Report.

Internal hernias (IHs) are a rare but potentially life-threatening cause of bowel obstruction, with a high morbidity and mortality rate if not promptly diagnosed and treated. This case report highlights the clinical course of a 75-year-old female who developed a transverse mesocolic internal hernia, a subtype of transmesenteric hernia (TH), following a Hartmann reversal procedure. The patient presented to the emergency department (ED) with a sudden onset of severe, diffuse abdominal pain. Her medical history was significant for systemic lupus erythematosus, pulmonary fibrosis, multiple pulmonary embolisms, and a recent Hartmann reversal procedure the month prior. Initial imaging suggested postoperative ileus, but the patient's symptoms persisted despite conservative management. Subsequent imaging raised suspicion of an internal hernia, and on hospital day 6, an urgent diagnostic laparoscopy revealed a herniated segment of the small bowel through a defect in the transverse mesocolon with herniation into the lesser sac. The herniated bowel was successfully reduced, and the defect was repaired. The patient had an uneventful recovery and was discharged in stable condition. Transmesenteric hernias, though more common in the pediatric population, can occur in adults, particularly following abdominal surgery. Diagnosis can be challenging due to variable symptoms and imaging findings. However, prompt recognition and surgical intervention are crucial to prevent complications such as bowel ischemia and strangulation. This case underscores the importance of considering internal hernias in the differential diagnosis of small bowel obstruction (SBO), especially in patients with a history of recent abdominal surgery. Early diagnosis and timely surgical management are essential for a favorable outcome.