It seems my POIS is gone, hopefully forever. I can explain how I believe it happened although I don't really understand what happened. In my previous posts I explained how Pepto Bismol prevented POIS when taken before O. This made me wonder if maybe there was something in the gut that was happening to cause the POIS symptoms. Well, about 4 months ago I came down with a salmonella infection and got quite sick. I had a fever for a few days and felt very miserable. I had diarrhea and lots of it. Whatever was coming out of me was black and disgusting, perhaps blood in the diarrhea. After I recovered from the fever the diarrhea persisted and I had to go on antibiotics (azithromycin) to kill off most of the salmonella. I started eating yogurt, kefir, and sauerkraut to try to re-establish a healthy gut microbiome. The diarrhea went away and my system normalized. But even now, almost 4 months afterward, it seems that my digestive system is different than it was before the food poisoning. I used to be quite gassy of a person. I like to eat healthy and that always resulted in a lot of flatulence. But now eating the same diet I DO NOT have excessive gas! Also, it seems that my feces does not smell as bad as it used to, which is strange. Anyway, the main point is that since this event I have not had any POIS! I have recently had multiple Os and have had no difficulty. This leads me to wonder what the heck might have happened. Was there a "bad" bacteria causing the trouble somehow that got eliminated in the sickness/ antibiotics/ recovery? I may be wrong but my gut (bad pun) feeling is that the current lack of POIS is related to the sickness/recovery somehow. I don't suggest this "treatment" to anyone, is wasn't fun, but maybe it can shed some light on the cause of POIS. Something to consider!