Re: Please help me with my son..
I would also strongly consider a new allergist. All my kids have had allergy testing before 1 year of age. I'd also consider going 100% dairy free, no milk, no yogurt, no cheese, no dairy ingredients at all.
Another possible product might be Duocal. It's a powder that you add to food to boost calories. It's dairy & soy free & from the people who make Neocate. My 2 year old is on Neocate Jr only due to his severe food allergies. He has no safe foods. I would speak to your dr before getting this but it can be a big help with children who need some help in the weight dept but with out foods that can cause allergy issues. If you son's stomach is bothering him, I might also think about a GI consult as well.
Mom to my girls ('94), ('99) & ('02)
And my little guy (12/09)