Jeanette_Isabelle, have you considered Pepto-Bismol (and generic) tablets as an alternate anti-diarrheal? My understanding is the bismuth salts have anti-microbial effects in the G.I. tract as well as mechanically slowing the movement of material in the tract. I made a half dozen missions trips to Peru amd Mexico 10+ years ago and had no G.I. problems while others in my group did. I made it a habit to take 2 tablets with each meal and 2 tablets upon retiring. I wouldn't call this proof, but if I ventured back to Peru I would certainly take my pepto with me.