Green’s Dictionary of Slang

release a chocolate hostage v.

to defecate.

1997		Eble Campus Sl. Apr. 7: release some hostages – defecate.
1999		Roger’s Profanisaurus 3 in Viz 98 Oct. 23: release the chocolate hostage v. To liberate Richard the Third after his imprisonment in your back porch.
2000		personal correspondence: release a chocolate hostage – to defecate. Have heard this one from a few people. e.g. ‘I’m just nipping out to release a chocolate hostage’.
2001		P. Meditzy ‘A Day In The Life Of...’ 29 Apr. 🌐 Later that evening I prepared myself for a night on the town with the boys. There’s no better preparation then having ‘baked one’ (held a shite back) for hours and then feeling the ecstasy of ‘releasing the chocolate hostage’.