Personally I have been using the product Gastrex from standard process, which is very similar to Okra pepsin E3; it's used to cleanse and heal duodenum, small intestine areas. It has Bentonite in addition but no pepsin as found in okrapepsin E3 (I do take enzymes with it however).
I have been taking it for 2 weeks and I havent experienced any dramatic results yet neithe was I expecting overnight results (it's more of a long term slow and steady approach to cleanse).
The Science is sound however and combined with a proper diet (which is critical) can slowly revert the gastrointestinal lining back to normal.