Which of the follow is most effective: pepto bismol, imodium, (loperamide) or kaopectate?

Effective at which?: Kaopectate basically is pepto bismol (bismuth subsalicylate). Both have bismuth salicylic acid which may have some antibacterial properties. Both are Aspirin products though and cannot be given to children or pregnant women or those otherwise intolerant of aspirin. Immodium does not treat the root cause of the diarrhea but has great stopping power. It wins.