Hello doctor, my baby is 3 month old and he is prematured by 2 month. After his birth he was separated from me for long time. I have no breast milk. therefore he is on exclusive formula feeding. My problem is that from 3 days he used to spit up whole milk which he take at a time. What can I do? Is this sign of indigestion? His weight is now 5 kg. which was 1700 gm at birth