I guess that I am one of the lucky ones, in that I have never had food "poisoning" or even diarrhoea since I moved to Thailand (15 years ago), and I do eat some street food. There have however, been incidents where I have eaten something which goes through me like an express train but then that's it. Any kind of fried rice is one such dish. I find it excessively greasy in Thailand, so now I don't eat it. I prefer steamed/boiled rice anyway.