| Summary points: | A 22-year-old male presents with a 1-year history of sporadic, bloody diarrhoea and recent weight loss. Medical history, physical examination, blood tests, flexible sigmoidoscopy revealing a large, polypoidal low rectal tumour, biopsies, emergency laparotomy, and postoperative follow-up are described. The authors discuss a rare case of sporadic mid-sigmoid carcinoma which had intussuscepted through the anus and provide a brief review of the literature. |