Types of lower GI bleeding

Neoplasm – bleeding can be from a polyp or carcinoma – Colon cancer is the predominant cause of neoplastic bleeding and is responsible for around 10% of rectal bleeding in patients older than 50 years – bleeding is usually low-grade, and is generally painless and intermittent – bleeding from these causes is usually occult – occurring as a result of mucosal ulceration or erosion from the surface of the tumor – though neoplastic bleeding can present as bright red blood per rectum, it is unusual for it to cause massive colonic bleeding.

Mucosal ulceration/erosion from the surface of the tumor GI Bleeding