What can i give my 1 month old baby for constipation?

Breast milk: Breast milk! Also, you could use glycerin suppositories for babies. That's it. Certainly no laxatives at that age.

Prune or pear juice: I usually recommend for babies of that age 1 ounce of undiluated prune or pear juice (available at the grocery store) for the baby one to two times a day as necessary. For recurrent constipation, some parents may need to give the baby a smaller amount daily to prevent constipation.