 [ Symptoms ] what causes bright blood and a dark brown vomit my father in law is a severe alcoholic and tried to stop cold turkey he is going on day 2 without alcohol and cigarettes and has vomited at least 18 times either bright blood or a very dark brown he refuses to go to the dr so any help would be great thanks for your help [ Disease ] is he drinking a lot of coffee perhaps that is causing the brown color bright blood means either a broken blood vessel in the esophagus or a bleeding ulcer in the stomach that last can be life threatening he needs to go to a doctor or possibly the er once stomach acid eats through the lining of the stomach and you start getting bleeding you run the risk of opening a larger blood vessel and bleeding to death so when he wriggles about it tell him you are not willing to see him risk his life and get him some help if at all possible