Why am I feeling severe pain across my stomach after exercising?

hi - I too run quite a bit and used to get this when exercising and when resting - I had it for years and it turned out I can't tolerate wheat and I would get shooting pains sideways across my stomach like stabbing knives. It's hard to describe but I never get this unless I eat wheat, even a small amount will do it. I did the blood test for Celiac disease (gluten allergy) and it didn't come up positive but I was already 3 weeks off wheat and felt so good I never wanted to eat wheat and then retest which is what I would have had to do to get an accurate measure. BTW, I'm a size 3 and am smaller, leaner and a flatter stomach since giving up wheat. Best thing I ever did - this also includes no barley, oats, hops, or bran. I can eat potatoes, corn, rice and quinoa which are better for you anyways. Don't know if this will do the trick but if you try it you will have to read labels as even Campbell's soup has lots of wheat additives. It's hidden in everything. Good luck!