Internal hernias are an extremely rare complication after pediatric liver transplantation, and its presentation with cholestasis has not been described to date. We report the case of a 12-yr-old boy who presented with moderate abdominal pain 11 yr after split liver transplantation and biliary-enteric anastomosis. He developed severe jaundice within 24 h of initial presentation. Imaging studies revealed ascites, dilation of the intrahepatic bile ducts, a dilated Roux-en-Y-loop, with the loop truncated at the level of the mesenteric artery, which performed a narrow right-to-left loop. At laparotomy, a transmesenteric internal hernia at the root of the jejunal mesentery was identified, originating from the creation of the Y-loop; the Roux-en-Y-loop and its adjacent intestinal loops had slipped through the opening. The Roux-en-Y loop was ischemic from strangulation, and the rest of the intestine well perfused. No surgical resection was necessary following reduction. The patient recovered completely. We discuss diagnosis and management of internal hernias, and review radiological signs. Internal transmesenteric hernias can occur at any time after liver transplantation and prompt diagnosis and surgical treatment are vital.