I wish I could answer that as I've wondered too but the ingredients just say Rice. This is a problem I have with my milk as well as I can not find one that doesn't have brown rice.
I did a little more research on the Bentonite Clay and kind of wish I hadn't. First of all, there's no consensus on who or what IBS it may help with different sources saying it's good for D but not C and vice versa. I somehow got to looking at Neomycin...again contradictory reports and I ended up getting into SIBO. What a merry go round My head is spinning.