Neoplasia (both carcinoma and polyps) can produce acute lower GI haemorrhage, although this more commonly presents with occult blood loss.

Colorectal cancer is common in the UK and a frequent cause of cancer deaths. Incidence increases with age and a family history of bowel carcinomas is common.

As well as rectal bleeding, left sided large bowel carcinomas frequently cause altered bowel habit and abdominal pain.

Other causes of rectal bleeding (such as colitis) can predispose patients to developing neoplastic lesions.

Learning bite

A digital rectal examination can save lives by identifying a rectal carcinoma.