Could my baby be lactose intolerant?
It's highly unlikely. If your baby is truly lactose intolerant, it means that he was born without the ability to produce lactase, the enzyme necessary to digest lactose, the primary sugar in cows' milk and breast milk, but this condition is extremely rare in babies. (Between 5 and 15 percent of Caucasians and more than 80 percent of people of African and Asian descent eventually become lactose intolerant, but symptoms don't usually start until later in childhood or early adulthood.) A baby born lactose intolerant would be very sick right from birth. He would fail to thrive or gain weight because he would not be able to digest breast milk or formula and would need to be put on a special diet right away to survive.
That said, if your otherwise healthy newborn has very watery stools and is passing a lot of gas, he may have what is known as functional lactase deficiency, which means that he's not yet able to completely digest lactose. This is a temporary condition that's common in the first few weeks of life and may even persist for several months.
