What can i use for a super fast constipated baby?

Need more info : How old is your baby? Why do you think your baby is constipated? When was the last bowel movement? Was the stool soft or hard like pebbles? Is your baby breastfed or bottlefed?

Pear or Apple juice: For simple constipation, i usually start with pear juice (in the baby aisle), and mix it with the formula. So a 4 oz bottle of formula would hold 2 oz water, and 2 oz pear juice. The sugar brings water into the stool to soften it. Prune works too but only by itself. I do this mixture twice a day. If this doesn't work after 1-2 days, consult your pediatrician for more advanced measures.

What are you feeding: There are many foods that are "constipating" to a young baby being introduced to solids, things like bananas, raw apples, carrots and rice. Try to figure out if this is the case and modify your infants diet. Any fruit that starts with a "p" help you "go" , peaches, plums, pears, papaya etc. Always consult your doc so you both can determine the best course to take.