Giving prune juice to constipated infants is a common health tip, but is it safe and effective? Let's find out. Prunes are dried plums that are full of nutrients, fiber, and natural sugars. One type of sugar called sorbitol acts like a laxative and helps with constipation. As a result, prune juice also contains a lot of sorbitol and can help relieve constipation. However, prune juice has less fiber, so prune puree might be a better choice. When introducing foods around six months, you can try giving your baby whole prune puree instead of prune juice. Doctors usually recommend that children over one year old can drink prune juice in moderation, but prune juice for infants under one year is not recommended unless approved by a doctor.