Am I correct in assuming he has a serious drinking problem, as in alcoholism? If he's vomiting blood he probably has a bleeding ulcer or damage to his esophagus from pouring so much booze down his throat. I don't know the background of what led to this situation, so I'm making assumptions here. To begin with, you can go to the hospital and give it a shot (if you haven't done so before) and explain to him that he MUST seek help for his addiction. However, in his physical state I'm sure a doctor will tell him to stop drinking now or he'll die. Oftentimes it works. I've been in plenty of AA meetings where people have gotten sober because they had the choice to continue drinking or die.