And I think someone mentioned this also, but be certain to give nothing but his food. No treats, etc. You can add a little plain, fat free yogurt...it helps my girls with gas issues. Other than that don't give him one single thing that could cause allergies to come out....just feed his food:-)
I am so glad you are working with him. I know the food is a little pricey, but NB is very good, and hopefully it will resolve the health issues with your boy:-)