Blood on the toilet paper can mean anything, including hemorrhoids. It isn't necessarily a sign of alcohol-related disease (although alcohol can interfere with clotting and contribute to bleeding more than otherwise).
The alcohol is terrible for his diabetes and high blood pressure, though, and he might very well have other alcohol-related conditions. I'm just not sure blood on the toilet paper, standing alone, tells you very much.
The "scary" blood in bowel movements, from what I understand, is the black, tarry stool where it indicates internal bleeding. The fresh, red blood is more likely to be from hemorrhoids or something similar, though it should still be checked out to be sure.