writing tips/research? (tw emetophobia)

I'm currently writing some self indulgent bullshit and i was wondering if anybody knows anything about how like. throwing up works. and like why people gag and stuff. i found some stuff online i was just wondering for the sake of my fiction if anybody had insights into that.

for reference there is one scene where the character is physically made to gag which causes him to throw up but i was wondering if there is like a cooldown when it comes to bile, how much more could he hypothetically throw up if he had to again? as other circumstances may cause him to later in the story.

okay that's all! thanks!