Carol, My son had reflux, asthma, etc. when he was a baby. This was 20 years ago, but what they had me do was put rice cereal in his bottle of formula. I would get cross cut nipples so the thickness could get through. I'll tell you, this sure did make him heavy. Not fat, but we never had a weight problem. He was on formula until he was 2.
I hope the little guy can start putting on weight soon.
Sue