Corn syrup has often been used by parents to manage constipation in infants, though it is not always necessary. Often, just giving the baby as much as two ounces of water once or twice a day is all that is needed to soften the stools. For infants who are already on solid foods (five months or older), pureed prunes are another good way to treat constipation.
If you are going to give your baby corn syrup, the syrup should be put into water, not into the baby's formula, and just a small amount should be added. A teaspoon in two ounces of water is a reasonable amount. Corn syrup is sweet like sugar, and when it gets into the intestine it stimulates it to move the stool along. It also draws a little more fluid into the intestine, thus making the stools less hard. You don't want to overdo it though, because too much can cause diarrhea and change the balance of salt in the body very easily.