Can a baby get constipated from formula Switching your baby’s formula may make a difference in their poop, since their sensitivity to some of the ingredients in the original formula may have led to their constipation.

How Do You Treat Constipation In Infants?
If your baby seems constipated, consider simple dietary changes: Water or fruit juice. Offer your baby a small amount of water or a daily serving of 100 percent apple, prune or pear juice in addition to usual feedings. These juices contain sorbitol, a sweetener that acts like a laxative.
Does Iron In Baby Formula Cause Constipation?
Some medications or supplements can lead to a constipated toddler, including high-dose iron supplements or narcotic pain medication. The low-dose iron in baby formula does not cause constipation. SOURCES: American Academy of Family Physicians: "Constipation in Children." American Academy of Pediatrics: "Constipation."