The baby may have some indigestion. It can be treated with Xingpi Yang Er Granule, zinc gluconate oral liquid and intestinal beneficial bacteria such as Mamiai. Eating apple puree can also regulate the stomach.
My baby is anorexic, usually zinc-deficient. Take some zinc gluconate oral liquid, which is very useful. My baby was also like this when he was a child. Drinking a few small bottles will have an effect.