I have to say that it sounds as if you could have two problems. Firstly, blood on your toilet paper does sound like hemmarhoids, but I should get it checked out if I was you.
Also, unfortunately, alcohol can upset your stomach a lot and cause you to have diarrhea the day afterwards. Lager and beer is the worst and this is due to the gassy nature of it, the wheat and the yeast. Wine can also do this and it is due to the yeast and sugar content upseting your stomach.
Sometimes, if I drink for about two nights in a row, then I have a bad stomach afterwards, with stomach cramps and diarrhea.
If I were you, I would cut down on your alcohol intake and see if your stomach improves.
It could also be that your liver has become overloaded with the alcohol, so it might help to cut down and start taking some Milk Thistle to help your liver.