An uncommon diagnosis of a common presentation of mass per rectum.

Introduction - In adults, protrusion of intussuscepted sigmoid growth through the anal canal is exceedingly rare, with only 9 cases being reported till date. Case Report - A 52-year old man presented to emergency department with what appeared to be an episode of rectal prolapse following straining while defaecating. On examination, he had a prolapsed 8 × 8 cm bowel, with a 2 × 2 cm friable villous growth as the lead point, with space between the mass and the perianal skin. Computed Tomography of the abdomen was done which was suggestive of telescoping of the sigmoid into the rectum protruding out through the anal canal with features of intestinal obstruction. He underwent exploratory laparotomy with sigmoidectomy with Hartman's Procedure. Post-operative period was uneventful. Histopathology was suggestive of moderately differentiated carcinoma. Discussion - In colo-anal intussusception, as was in our patient, the preferred approach is to reduce the intussusception before resection, to perform a sphincter saving operation as compared to an Abdominoperineal Resection (APR) otherwise. Conclusion -A high index of suspicion is important to diagnose and treat such cases early to avoid lethal outcomes by misdiagnosing it as simple rectal prolapse.