Thanks everyone for your replies and the tips! I've narrowed it down to just large amounts of regular milk that upsets my stomach and bowels. I've switched to soy milk (I actually like the taste of the soy milk a lot better than the regular milk) and have noticed a huge difference. Yogurt and cheese don't seem to bother me.. I haven't had ice cream in over a year or so, so not sure about that but I seem to recall having some issues with ice cream in the past, but I can't quite remember exactly so I may have to do some trial and error with it someday.

It's funny, I never knew a person could develop lactose intolerance or a sensitivity to milk at any age.. I thought one had to be born with it. I guess you just never know eh?