Diffuse cavernous hemangioma of the rectum is an unusual lesion. We reporting the case of an 18-year-old man with a rectal cavernous hemangioma in whom recurrent rectal bleeding and marked anemia were thought to be caused by his co-existing internal hemorrhoids. This resulted in a 2-year delay in reaching the correct diagnosis. Digital rectal examination revealed a walnut-sized, wide-based, elastic, soft mass 3 cm proximal to the anal verge. Colonoscopy revealed a bluish, submucosal lesion with superficial capillary dilatation at the same site. Arteriography demonstrated vascular tumours in the territory of the right hypogastric artery and the superior rectal artery. In 1972, Parks and co-workers described resection and colo-anal sleeve anastomosis as an alternative operation in the treatment of this rare malformation. We will describe the clinical presentation, diagnosis, and long-term results in a patient with this condition managed with this surgical technique. The patient has done well without any recurrence of rectal bleeding for over 10 years since his operation. Resection with a colo-anal sleeve anastomosis offers major advantages such as a lower risk of intraoperative bleeding, no risk of damaging the pelvic nerves, sparing of continence and avoidance of a permanent colostomy. It should therefore be considered the treatment of choice for this uncommon condition.