A case of constipation and bleeding PR

A 58 year old male was referred for bleeding PR. He was bothered by constipation for quite some time. About 6 years prior to this he had similar problem of bleeding and had flexible sigmoidoscopy where an ulcer was seen on anterior rectal wall. For six years he was taking herbal laxatives. He denied any fever, loss of weight or anorexia. Blood was bright erd in color and on stool surface. At sigmosidoscopy he had an indolent looking ulcer with hyperemic edge on the naterior rectal wall some 7-8 cm from the nal verge. Mucosa up to splenic flexure was otherwise normal.

What questions you will further ask? What is the diagnosis?