What can i do for my 3 month old he is having hard stools how can i relive them?

See below: If the child is bottle fed mostly, replace one bottle a day with a baby juice like prune, pear, etc. The increased sugar content in the juice and other components should start to soften the stool. As a last resort if the child is straining to push out a stool, a piece of a glycerin suppository placed in the rectum can help the stool to slide out.