I give my guy a few spoons of prunes with lunch every day and that helps significantly. He's been having constipation issues since we started formula at 3 months
My daughter typically has issues when she's slightly dehydrated... so I get some Pedialyte and really push her to drink... that typically does the job... we also give her grape water Kiefer (just the tiniest bit at a time)... it helps the good bacterial in your digestive track... so things keep moving along.