my son has tried to switch from snowbrand Pure to A+, and he had diarrhea for many days too. The diarrhea stopped right after I stopped trying to switch. I called A+ nurse and they also think that he might be over react to some of the ingredients. So my son is drinking snowbrand Touch, which he had no difficulty during the switching period at all.
A+ nurse said 3-5days of trying is good enough, if diarrhea continues, I think u should think of switching to another brand.