Hello -- In addition to making sure he is not intolerant to other common allergens such as dairy, soy, nuts, etc.  (this can be done by following a simple elimination diet)  have a read of this: http://www.celiaccentral.org/News/NFCA-Newsletters/Celiac-Central-Newsletter/182/#GlutenFreebutStillill Did your nephew ever do any ...

You don't need to spend any money or have any expensive treatment.They may help but will not reach the cause so have just a sticking plaster effect. The cause is 99% sure to be dairy products. Avoid them completely, even a tenth of a teaspoon can cause problems, until you are symptom free. This could take anything up to 3 months ...