If your baby has recently has a stomach virus and is exhibiting symptoms like green, frothy stool and diarrhea, his pediatrician might diagnose him with lactose intolerance. This condition is different from normal lactose intolerance, which develops over time as the body stops producing lactase, the enzyme that helps digest lactose in milk. Instead, lactose intolerance in a baby after a stomach virus is a temporary condition.
Cause
Sometimes when a baby has a stomach virus, the invading virus and immune system response damage the cells lining the intestinal walls. If the baby has severe diarrhea as a result of the infection, lactose intolerance is even more likely to develop. In adults, these intestinal cells would rapidly heal themselves, but an infant has an immature digestive tract that cannot fix itself so easily. The damaged cells include ones that normally produce the enzyme lactase, which leads to a temporary condition of lactose intolerance until the intestinal lining heals.
Treatment in Formula-Fed Babies
A formula-fed baby may need to switch from a normal cow's milk-based formula to a special lactose-free formula or soy formula for a few weeks. You should only switch formulas under the guidance of a doctor, since not all formulas are nutritionally equivalent. Otherwise healthy babies who are over 3 months old and who exhibit only a mild temporary lactose intolerance might be able to stay on their normal formula, according to the American Academy of Family Physicians.
Treatment in Breast-Fed Babies
A breast-fed baby who develops lactose intolerance after a stomach virus should continue to eat breast milk. Breast milk contains immunological factors and other components that actually aid in the healing of the intestines, so providing these is more important than restricting breast milk because of its lactose content. The amount of milk a breast-feeding mother drinks has no impact on the lactose content of her milk, so you don't need to stop drinking milk yourself if your baby develops a virus-induced temporary lactose intolerance.
Considerations
Lactose intolerance from a stomach virus does not increase the chances that a baby will develop the normal type of lactose intolerance later in life. In general, the goal for dealing with lactose intolerance in a baby caused by a stomach virus is to keep the baby on his normal food if possible and if a lactose-free formula is required, to return him to his normal food as soon as the intestines are healed. The long-term consequences of feeding a baby food that contains no lactose remain unknown, according to pediatrician Dr. William Sears.
