I had a stool this morning that is very dark brown/black. not tarry or smelly. i take no medication except vitamin. i drank wine last night. blood?

Dark stool: Iron makes the stool black, so if it in your vitamins that could be the cause . In fact the reason blood makes the stool black is because of the iron in blood. Discuss with your doctor /urgent care over next 2 weeks

Possible: Digested blood in stool turns stool coal black. It is often blood coming from the upper G-I tract like an ulcer or gastritis. There are other things that can cause a black stool such as pepto bismal(bismuth) or iron which is probably in your vitamin. Alcohol in excess can cause a gastritis which could bleed. I believe there are over the counter tests you can purchase to check for blood.