Extensive ano-rectal varices were diagnosed by transrectal ultrasound (TRUS) in a patient with portal hypertension who presented with an altered bowel habit. The diagnosis of ano-rectal varices is usually made by direct inspection during procto-sigmoidoscopy in patients who present with rectal bleeding. However, the sigmoidoscopic and barium enema appearances of varices may mimic that of a tumour. A firm diagnosis can readily be made using TRUS and the local extent of varices clearly mapped out.