Lactose intolerance.

For some years I did not drink milk, but started to take a lot of milk just recently and discovered I cannot digest milk without developing a lot of gas, stomach aches, etc. I did not have that problem before I stopped drinking milk. Will I develop more lactase, i.e., the ability to digest milk, as time goes on and I drink more milk, or will I have to take Lactaid milk for the rest of my life (it's not available in some countries).