Parents of children with mild food allergies?

My daughter who is 9 years old has always had stomach aches and diarrhea. There were sometimes when she didn't make it to the bathroom. Finally I had a doctor who suggested she was allergic to wheat, and to try a wheat free diet for 2 wks and see if that helped. We did it, and it did help! It is the hardest diet in the world to follow though!!