Your son has two positive blood tests for celiac disease, plus a positive biopsy for it...why hasn't your doctor diagnosed him with celiac disease, which is the most likely diagnosis based on the test results you shared? The next step should be a gluten-free diet, which your doctor already recommended.     

I am glad to hear you are not taking acid blocking meds as they increase gut PH which inhibits mineral absorption which, in turn, often causes the body to rob it's own bones of the calcium it needs for various metabolic processes. I was asking about that because acid reflux is very common in the celiac community.

I am not taking anything except for the multivitamins that I purchased from the supermarket.

The critic acid and sodium citrate is corn unfortunately and they don’t have to label corn because it’s not part of the top 9 allergen and not mandatory 😭