I thought soy and goat's etc were not recommended for kids under 2? If you are concerned about an intolerance I would be seeking a professional opinion, it's not something that should be ignored. And jumping around to different products could make things worse rather than better. For instance, a number of people who are lactose intolerant are also soy intolerant.

Good luck with finding a solution

ETA I was wrong about the goat's milk, sorry! That's great info though, thanks