Yes, it does have it. However, I would guess the ratio is small since it has over 100 herbal extracts in it. I'd still give it a try. I'd order direct from MH by calling, but I'd wait a few weeks because he's on a trip to FL.
I'm not quite sure why you'd have a bad reaction to cascara sagrada (are you sure its just not doing what its supposed to?), but if so, I suspect you probably have a problem that manifests itself while taking it, and maybe the herb itself is not the problem? What happens to you?