An unusual case of a colonic vascular anomaly resembling angiodysplasia associated with right sided diverticular disease is presented. The patient, a 74 year old man, presented with a four day history of rectal bleeding and subsequently underwent hemicolectomy. The resected specimen was flushed out with heparin-saline solution and injected with a barium-gelatine mixture. Preoperative barium enema revealed right sided diverticula, whereas post-resection angioradiography revealed the "coral reef" vascular anomaly consistent with angiodysplasia. Histology confirmed the presence of both diverticular disease and angiodysplasia. This case report highlights the importance of considering a vascular anomaly in patients presenting with rectal bleeding despite the presence of another radiologically demonstrable anatomical lesion.