The question often comes up as to whether goat's milk might be tolerated better than cow's milk by lactose sensitive individuals. The short answer is: probably not. Goat's milk does have slightly less lactose than cow's milk, but probably not enough to make a difference for most people. (Note that the proteins in cow's milk and goat's milk are different enough so that some people with an allergy to cow's milk may be able to consume goat's milk, but that is really a separate subject.)
What about that delicious goat cheese that has become so popular? How does that fit into the FODMAPS elimination diet? Like cow's milk cheeses, there is less lactose in cheese because most of it is carried off in the whey, which is separated from the curd during the cheese making process. However, because it is not an aged (or ripened) cheese, goat cheese does have a small amount of lactose in it. It can still be eaten, even on the elimination phase of the diet, if the portion is small. Like other non-aged cheeses, the portion of goat cheese should be limited to 1 oz during the elimination phase of the diet.
Lactose, also know as milk sugar, is the predominant carbohydrate in milk of any species: cow, goat or human. People who don't produce enough of the enzyme, lactase, can't digest lactose. They experience, bloating, gas and diarrhea when they consume it.