It is important to determine if the bleeding is fresh bright red or dark, and whether it is on the surface of the stool or mixed in. Bright red blood on the toilet paper after wiping is usually due to haemorrhoids. If the blood is mixed in with the stool, or associated with various abdominal symptoms, other pathology should be sought, in particular gastrointestinal malignancy. Black, tarry, offensive smelling stool is digested blood (melaena) and originates from the more proximal intestine. However, occasionally large upper gastrointestinal bleeds (e.g. varices, peptic ulcers) can cause fresh rectal bleeding, although usually the patient will show signs of volume depletion such as hypotension, postural drop and tachycardia. Rectal blood may occur with infection or inflammation of the bowel (colitis). It is important to consider gastrointestinal malignancy in any case of rectal bleeding.