I have also found the following useful when trying to ease baby constipation and constipation in newborns.

Exercise is very helpful in eliminating constipation. If your baby is mobile, get him to crawl or walk more. If she is too small to crawl, lay her on her back and rotate her legs
yourself. Bend and straighten her legs and tickle them to get those legs kicking.

Massage the baby’s belly. Using a natural oil or cream, rub your baby’s tummy in the belly button area in small circles.

Give the baby a warm bath. A warm bath will help to loosen the stools and allow your baby to go to the bathroom. Do not let the water get too warm however so as not to burn the baby.

Hope that helps