he will need an GI consult after evaluation by the ER physician. They will run bloodwork and probably scope him..(might be a NG tube, IDK), depends if it is just his esophagus or the fundus (upper) stomach. it is best to get him in there although they most likely will not run any big tests tonight unless it is an emergent situation, it's a holiday, the doctor needs to be called in. Emergent would be continuing to vomit blood or passing it through his rectum.
it's hard to assess anything when the causes are so variable, age, physical condition, amount of alcohol he is currently drinking and for how long, is he a smoker, you get the drill