Lactose Intolerant?

Hi.

I used to always drink regular cow's milk. Then I switched to original soy milk and I love it. Now when I drink cow's milk, I get an upset stomach. I asked my family doctor if I'm lactose intolerant. She said "No" because I can have yogurt, cheese, ice cream etc and I'm fine. She said the regular kind is naturally heavy and is common for people to get an upset stomach from it.

She recommends me to drink soy, because it is better for me.

A friend of mine is lactose intolerant. I was told people can develop become lactose intolerant. I didn't know that. I thought people were born with it.  Is this true that people can develop it?  Is there a chance I can since I can't drink cow's milk any more?  Should I be watchful and keep an eye on it?

Thanks in advance.

[Paxiled]

Only a few ethnic groups have the enzyme that digests dairy, mostly in India and Scandanavia.  Then there's the intolerance problem, and then there's the allergy problem.  So there are three potential problems with dairy.  Soy is also a common allergen, but you seem to be okay with it, but dairy and wheat are quite common because neither is natural human food.  Humans invented wheat and no other adult of any species drinks milk past the age of weaning.  Yogurt and cheese tend to be easier to digest because they are cultured.  Goat's milk and sheep's milk and other animals milk is easier to digest as well.  Cows have a very odd digestive system, and they were also invented by humans -- no wild cows out there.  Probably hybridized from oxen and buffalo in order to make a very fatty and docile animal.  Ice cream, on the other hand, is delicious, but isn't easy to digest for anyone not just because of the dairy but the high amount of fat and sugar.  Okay once in a while, but obviously we don't eat it for food value.  Most people don't notice food sensitivities until they get older and the sensitivities wear down the system and end up in disease states such as arthritis or immune system problems or digestive problems.  Perhaps you just reached that point.