I would like to know where you get your information. It is EXTREMELY rare for a baby to be lactose intolerant. It is pretty often that babies have an allergy to the cow's milk protein (casein). When the mother ingests it, it is expressed in her milk. The baby's immune system sees it as an invader and produces anti-bodies to fight it, causing stomach upset because stomach lining is actually shedding. That is why with some sensitive babies you can see blood in the stool.
In general, however, the ability to digest lactose is a genetic mutation. That is why populations who have never had it in their diet (Asia and parts of Africa, for example) are mostly lactose-intolerant. Those of us who can digest cow's milk are actually evolutionary mutants. My reference for this is Kingsolver's Animal Vegetable Miracle.
Neither DH or I have a single allergy between us, yet our son has an ongoing allergic reaction to dairy.
Also, OP, keep in mind that it can take about two weeks for you to see results of the elimination, as the protein lingers in your system for a while.
Originally Posted by foreverinbluejeans
Some people think their baby reacts to cow's milk protein in their breastmilk. This is actually very rare... Both parents have to have problems for the risk of the baby having problems with cow's milk from human milk to increase beyond rare. If both parents don't have bad allergies (not just hay fever) there is little chance cow's milk is going to be a problem.