Green’s Dictionary of Slang

(Aus.) a metaphorical internal organ, presumably connected to the anus, which is agitated in times of stress.

1982		P. Radley My Blue-Checker Corker 7: ‘Blowin’ that thing like it’s Judgment Day...he’ll end up bustin’ his poofa valve!’.
2012		Urban Dict. 14 Jan. 🌐 Poofer Valve The anus hole When you see someone lifting a heavy, you would say Slang: ‘dont blow ya poofer valve’ Translation: "please do not prolapse your anus everywhere my friend".
2024		https://www.reddit.com/r/AustralianNostalgia 🌐 AmorFatiBarbie: I knew a man wasn't for me when I said to him ‘I almost blew my poofer valve’ and he gave me a lecture on how that term wasn't medically accurate [ibid.] Arcencie 48: I’ve always called it a foofer valve!