hi doctor, my baby is 3.5 months old and primarily on formula milk . from last few weeks he is doing greenish poop. earlier it was yellowish in colour. I am but worried. is this normal

A. hi dear In some babies, the iron sulfate in a supplement or iron-fortified baby formula can make dark-green​ stools, or sometimes even greenish-black. There is no need to be concerned with the color change, as it has no significance to your baby's digestive system.