Hmm, there could be many reasons why he's suddenly not finishing his milk. Is 3 oz what he's been taking since birth or? Their stomachs are still quite small at the moment so that might be a reason your son prefers smaller but more frequent feeds! Another thing is, is there a reason why your son is on NAN HA formula? It's a hypoallergenic formula meant for babies with cow milk allergy, so you can go with the normal NAN Optipro if he doesn't have it. Reason being, it's further broken down and some also may feel it tastes bitter!
Jena Lim Xiang Ying