Colonic Dieulafoy's lesion is an unusual source of massive lower gastrointestinal haemorrhage. It is characterized by severe bleeding from a minute submucosal arteriole that bleeds through a punctuate erosion in an otherwise normal mucosa. We describe an elderly man who presented recurrent rectal bleeding from a Dieulafoy's lesion in the sigmoid colon associated with bizarre colonic vascular malformations and an abnormal von Willebrand Factor. He was successfully treated by endoclips application. The clinicopathologic features of this unusual association are discussed and suggestions are made for diagnosis and management.