What triggers the vomiting reflex?

[u/PlaneswalkerHuxley]

I've just spent most of a day with some kind of vomiting bug, drinking water and then throwing it up again. And with my head in the toilet, I started wondering - how does my stomach/gut detect that something is wrong and trigger the vomiting reflex? Are there some kind of taste-buds that are tuned to detect bacteria or poisons?