Lactose is a sugar naturally present in milk. The ability to digest lactose depends on the presence of an enzyme called lactase. A small percentage of infants about 1 percent to 3 percent of all babies are born without the ability to digest lactose. They develop abdominal cramps, bloating, watery diarrhea and excessive gas if they drink more than a small amount of milk. For these babies, soy formula is the food of choice.
Parents sometimes consider switching to soy formula when a baby has colic, spits up or is fussy.
It is best to check first with your baby's health care provider. Some fussiness and irritability are normal for newborns. If you choose to give your baby a soy product, an important distinction is in order. Be sure to choose a soy infant formula, not soy milk. Soy milk is not nutritionally adequate for infants.