Quicker than lager turns to piss literary phrase
Very quick
Very quickly
Very fast.
Extremely fast as if having been abruptly startled or shocked
This phrase derives from the 1980s in the UK. The earliest citation can be found in a poem Beasley Street written by John Cooper Clarke,
If someone has a cast iron stomach, they have a strong stomach that can digest unusual food and even bad food without being ill.
Jimmy must have a cast-iron stomach, when he drank milk with lime juice and felt perfectly fine afterward.