<s>[INST] My son has been on the Enfamil Newborn and he is about to turn 4 months and he does not poop regularly and I feel like its the formula, but I’m not sure what to switch to since he has to soon anyway. He has some gas and it does not look like the less pooping is bothering him, but I know he should be pooping more than he is. We tried Gerber Gentle and he hated it. I’m thinking about Similac but I’m just not sure.. Any suggestions??? [/INST] constipation is common in formula fed infants . this problem increase if the milk is not prepared in proper concentration. Add 1 scoop of milk in 30ml of water and maintain this ratio when preparing the milk in whatever amount. Use the scoop in the container to measure. Passing stool once in 3 days is tolerable, give him glycerine suppository per rectal if the frequency is still less. Change of formula will not help. </s>