Oh man, Sorry to hear that John. I still think it is gut related (especially since while on Pepto Bismol for two weeks I had zero symptoms, and you mentioned something similar.)
I?m doing an experiment by taking some Bismuth Subgallate, to see if I have the same disappearance of symptoms... to me, that would rule out the salicylate (aspirin) in Pepto Bismol, and most likely mean that the Bismuth action in the stomach is the main actor. If that works it at least hints to me that it can be fixed by some means of altering the gut (not sure what yet though).
Will update once that experiment is complete.