If your son is celiac, and you want an official diagnosis for him, you will have to have him continue eating gluten for the testing to be accurate. The antibodies the tests look for start to disappear in the absence of gluten. Stomach pain, joint pain, migraines, irritability, iron deficiency.... all of these can be celiac and he should be tested for it before he goes gluten free, because to restart gluten later could make him very sick.
I probably should have him tested for celiacs instead of just going gluten free without a diagnosis. If I don't he will always be labeled by the pediatrician and school as psychological. I don't want that for him. Thank you for your input.