Presence black stool
is indicative of slow loss of blood in the intestine. Usual
source is the lower part of the esophagus
or the stomach lining. It is possible
to have small ulcers , aggravated by ingestion of alcohol and drugs like aspirin
or other NSAIDS. Bright red blood on the tissue after wiping may
indicate small fissure or hemorrhoids.
Even if he is on acid controlling medications, unless his eating and drinking
habits change , the problem will continue. If he has not had an endoscopic
examination of the esophagus and stomach , he should do this ASAP. He needs
to have a complete blood work including blood count, liver
Wish him well.