We stumbled upon an infant constipation remedy that really works every time for us. We searched on the internet and saw a lot of remedies:
molasses, putting thermometers in the anus, taking warm baths and baby laxatives.
The best natural remedies that have worked for us is to first avoid foods that cause constipation like bananas and cheese.
The best non-prescription remedy that we have found is the Russell Stover Sugar Free Jelly Beans. Start off with 5 jelly beans and if that
doesn't work go to 10. I kid you not, it works for us every time and our daughter is 20 months old. Its also not too hard to get a baby to eat a jelly bean. I think it works because of the sugar alcohol. If you look on the back of the bag it even tells you that the product may cause a laxative effect.
Let me know if it works as well for you as it does for us.