There are two ways to treat lactose intolerance. One way is to avoid products that contain lactose, such as milk and dairy products like cheese and yogurt. Another way to treat lactose intolerance is by taking the enzyme itself, either in liquid form or a pill form, and it's called lactase.
The most important thing to do is read all the labels. A lot of different things have milk in it, a lot of things have lactose in it, so anything like milk chocolate, a TV dinner, you just don't know what has milk, so you have to read the labels. The other thing is that people with lactose intolerant are at risk for osteoporosis, so you have to take supplements for calcium and vitamin D to avoid that problem.