Any spicy food. I fucking love mexican foods. Spicy chilli is one of the best things in the world. Used to be able to eat it all the time as a kid and it was never spicy enough, but now as an adult I can't touch the stuff without having the runs the next day.
I have a cast iron gut- unless I'm eating fast food in Colorado for some reason. Every time I've passed through the state I've eaten something that's made me spend half a day on the toilet.
It seems every time that I eat my oats for breakfast, I end up on the pot in the afternoon and I have the worst-smelling-never-ending gas all day long.