Multiple venous malformations in the left colon and rectum: a long-standing case managed conservatively and an update of current literature.

Venous or cavernous malformations of the colon or rectum are a rare cause of lower gastrointestinal bleeds. It has been previously described as a diffuse cavernous haemangioma which was thought to be a benign vascular tumour. It mainly affects the rectosigmoid area of the gastrointestinal tract and is most common in children and young adults. Misdiagnosis is common with patients averaging a total of 19 years delay to this final diagnosis. We report a case of a 65-year-old patient who presented with occult, painless rectal bleeding and prior to this presentation, had been managed variously as colitis and angiodysplasia. This article aims to delineate the updated classification of this disease, principal clinical clues to aid the diagnosis while discussing patient treatment options and potential challenges faced in patient management. © BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.