Sir my five months old baby has white substance under his penis foreskin what to do

A. There is nothing to worry I guess. This is just a usual discharge due to the shedding of the skin cells from the inner foreskin of the baby's penis and looks like milky white and it's called smegma. But if u notice a way too much discharge with a swollen or reddish penis then there could be a infection. Otherwise you can gently wipe it away with a soft and clean cotton cloth dipped in warm water.