Have you tried eliminating dairy?
I was feeling better on the gluten free diet, but notice now diary is starting to bother me.
I've switched to Lactaid milk for recipes requiring milk (like cream soups), but haven't noticed much of a difference. I would hate to give up cheese because I use cheese as snacks to replace those gluten snack type things.
I may have to eliminate it myself just to be sure that's what is causing the tummy distress. My distress is mostly upper abdominal--between the naval and rib cage. I also have IBS, so who knows what's triggering all of this? Stress? Well, unfortunately that's my middle name. LOL