Can you develope lactose intolerance all of a sudden?

Im 20 and have been able to enjoy milk and most other dairy products for as long as i can remember. But just in the last 6 months or so it has become almost impossible to have anything dairy. Today I ate one slice of cheese pizza and my stomach started...

I know that it's the lack of the lactase enzyme and it's something you're born with, but can you also develope it at a later date? Is there any medication or diseases whos side effect is lactose intolerance?

Can a blood test be used to test for lactose intolerance when not combined with drinking a lactose solution? I've been having a lot of stomach trouble this year. After tests for infections, parasites, etc came back normal, my PCP took a blood sample...

I think my 4 year old daughter is developing an intolerance to lactose. She has been complaining of off-and-on pains in her stomach for the last month or so, and just this weekend threw up twice after drinking chocolate milk or eating nachos. I was wondering...

hey all, so I've been diagnosed with lactose intolerance. I've changed my diet dramatically, but I know there are still some foods I'm eating that I don't even know have lactose in them. First question,does mayonaise and ranch have milk ingredients ...

I'm trying to read up on Lactose intolerance but they keep changing the words they use to describe it and it's pretty confusing. I know that Lactose Intolerance == Lactase non-persistence, but then they start talking about Lactose Persistence/non-persistence...