How deadly would it be to drink or rinse mouth in tap water in third-world countries for someone from a first-world country with GI problems?
I have several chronic GI problems, also had huge GI viral infections when young. I probably have thrown up during my childhood more times than most adults have in their whole lives combined. Now I have GORD (acid reflux) and functional dyspepsia. I am from San Francisco, USA, and I do not even drink tap water here. It is a missnaming to call the USA a first-world country, but for this post I will call it as such for this hypothetical.
My girlfriend's brother went on holiday to Da Nang, Vietnam, accidentally brushed his teeth with tap water, then got his GI system absolutely obliterated, bedridden with fever, throwing up and diarrhoea for a week. And this guy has a much stronger stomach than I do.
So I got thinking, how fraught would it be for me if I did the same as he did and brushed my teeth in or drank tap water either there or in third-world countries like Mexico, Pakistan, Thailand, Jamaica, Brazil, etc.? Would I likely get destroyed?