My baby not pooping for 4 days, he is on breast milk completely. Is this is nay matter of concern or is it normal?

A. Don't worry this is normal, If your baby is only being breastfed they may not poop every day. This is because their body can use up almost all the components of breast milk for nutrition and there is very little left that needs to be eliminated. After the first 6 weeks or so they can go even a week or two without a poop.