I find if I eat at Taco Bell I get cramps later on... which I avoid because of that reason. Nothing I can't deal with. It's only a problem if I eat for dinner / later at night and then I wake up at like 5am because, I guess, my stomach's pissed at me for having the nerve to injest that stuff.
I know other folks have the opposite reaction, based on the 'run for the border' jokes.
That and Air travel seems to have some impact, regardless of what I eat. Otherwise I think my digestive system is rather healthy. Thanks for asking Doc.