Many parents have fussy babies, and sometimes they blame the babies' infant formula, citing a lactose intolerance. Lactose, or milk sugar, is present in breast milk, however, so this is usually not the cause of a baby's fussiness. Nevertheless, there are some babies who require a lactose-free formula, namely those who have galactosemia, which is the inability to digest lactose. Another reason for parents to temporarily switch to a lactose-free formula is a bout with diarrhea, which can cause temporary lactose intolerance. The different types of lactose-free formula include varieties made from cows' milk that has had the lactose taken out, soy or hydrolyzed proteins.
One type of lactose-free formula is simply formula made from cows' milk that has had the lactose removed. Usually, corn syrup and table sugar, called sucrose, are added to the formula in place of the lactose. This type of infant formula might help babies who cannot digest lactose, either temporarily or permanently, but they are not appropriate for babies who are allergic to cows' milk, because they still contain milk protein.
A baby who is unable to tolerate cows' milk might be switched to soy formula, which is another type of lactose-free formula. This type of formula is also appropriate for vegan families who do not want their babies ingesting any animal products. One problem with using soy formula in a milk-allergic baby is that many babies who are allergic to milk are also allergic to soy. There also is some speculation that soy formulas might cause growth problems, particularly in babies who were born very small or prematurely.
For babies who cannot digest lactose or soy, some pediatricians recommend a formula that is made from hydrolyzed, or predigested, proteins. Other reasons to give hydrolyzed formulas include frequent rashes, colic or other symptoms of an allergy. These lactose-free formulas are very easy to digest for babies who have allergies. These formulas typically are quite expensive and might cost three times as much as traditional milk-based infant formulas.
In all cases, parents should consult with their child's pediatrician before deciding what type of formula to feed their infant. Most babies do well with cows' milk-based formula. Even if a baby is colicky, this is not necessarily an indication that the baby is lactose intolerant or that a lactose-free formula is needed. Switching formulas can cause further digestive upset, so it should be done only under the advice and supervision of a doctor.