A 49-year-old female with morbid obesity (BMI 42) underwent laparoscopic Roux-en-Y gastric bypass (LRYGBP). 10 months after the operation, she presented to the hospital with intermittent mid-abdominal pain. An internal hernia of the sigmoid colon through a mesenteric defect of the jejuno-jejunostomy was found. Although small bowel internal herniation has been widely documented, the finding of large bowel internal herniation has not been previously reported. Maintaining a high index of suspicion and a low threshold for urgent intervention are required when evaluating patients with vague abdominal complaints after LRYGBP.