Why does cheap beer make me fart?

I drank a bunch of cheap beer last night. High Life, PBR, etc... I wanted to sleep in this morning, but every ten minutes I'd wake myself up with an amazingly loud fart. It was funny at first, but now it's really annoying.

I don't notice this effect from other alcohol. I also don't notice it with more expensive beers. What is it about cheap beer that gives me thundering farts?

Cheap yeast in the brewing process? Couldn't really say for sure.
When I drink beer with a lot of hops I get mad shits the next day. Phone Post 3.0

Did you end up drinking an assload more beer than you would craft beer because of the alcohol content? Maybe you swalled too many bubbles or something? Phone Post 3.0

Is it that you enjoy smelling your farts after you drink and expensive beer because you are feeling snobby?

Makes me piss out my ass, not fart. Consider yourself one of the lucky ones.