I was on soy milk for the first 5 years of my life.
I was always getting sick as a kid. I grew out of the lactose intolerence though at around age 5. The only negative thing to come out of that is, I don't like milk. Can't drink it or stand the taste.
But it's possible! Those upset belly's are bad news! I'm glad you all found out what the problem is. She's a beauty!