Answer:
he may have an ulcer that is irritated by the alcohol, which is a poison. He should see a doctor and be tested for an ulcer
What is it he's drinking, could be that...!
Could he be drinking a little too much? It might be blood, or something he ate earlier that was colorful. Also, did he drink a colorful alcohol? If it's dark brown and looks like coffee grounds he should see a doctor, that could be stomach bleeding.
It depends on what he has eaten, and what he has drank in the last 12 hours.
Meat takes a long time to digest, and will come up hours after you have started to drink booze, so will anything that you have put in your stomach for the last 12 hours or so, if its greasy, because its harder to digest than foods such as starches.
I wish you well...
Jesse
I drank a 1/5th or more everyday for over 10 years and got to where I puked every morning. It was just part of my wake up routine as I started each day. My puke varied in color depending on what I had munched out on before crashing. Sometimes it was real thick and chunky and others as thin as tomato soup. The coloring comes from the contents of the stomach and sometimes a little blood. I only stopped because I almost died. No big deal.