Hi, well I've been having bad allergy symptoms for awhile; sinus congestion, ear 'fullness', runny nose, etc.. I finally went to an allergist last Fall. She tested me for all kinds of environmental allergies, and milk, eggs, wheat, soy, peanuts. Turns out I was allergic to wheat! Among others like mold, cats, certain grasses, trees, and weeds.
Anyway, I have been having stomach issues for about 5 years or more---could have possibly been wheat. It's not celiac disease though, thank goodness.
I read that foods we eat over the course of our life can become harder to digest, hence causing allergies or sensitivities.
Now I'm 99% gluten (wheat) free. The 1% sneaks in here or there :)