I used to be like that - I never got as far as throwing up in my bed, or pissing myself, but I have done everything else on a regular basis. Friend/flatmate said, constantly, that I don't know when/how to stop, and eventually I forced myself into slowing down my drinking to the stage where I can now go out for five or six hours in a pub and not come away unable to see, walk or talk. Depends whether he realises he doesn't know when to stop, or if he even cares really, as to whether he can tone it down for the sake of everyones sanity (and his organs).
I think you need to speak to him. Which will be difficult, but it sounds like he has a problem that's more than just a bit of antisocial behaviour towards housemates.
He has damaged the property. Either tell the land lord or tell him when he gets back that the landlord has inspected the property as he is considering selling it and is not happy with the state its in. As you and your flat mate look after it you do not think its fair you will all be thrown out because of him so he has to leave. Is it possible he signed the renewal so its in his name as he suspected you wanted him out?
He didn't, but he does now... Didn't take to kindly to his talk. Pleasant side effect though, he's stopped talking. Woop woop!
