I live in the southwestern US, where it gets very hot & very dry. Apparently what they tell the naturopaths in school here is that clay can be hard for people to take internally around here. It might explain how i get a bit constipated with it, even when I take tiny amounts with lots of water that day. The idea is that you are taking in fluids just to keep up with what your body needs, because you're losing so much water to the environment without much humidity to balance it. Thus, some of us around here might need to avoid the use of clay. Just a thought - if you are having problems with clay, maybe it's the dry environment that is challenging you, if you live in one.
I've also been told we need to supplement with a lot of minerals, especially magnesium, because we sweat so much out here without realizing it.