Post-flush surprise 

A turd (seemingly with a mind of its own), which refuses to be flushed, for fear of god knows what. It sometimes intially appears to have been successfully flushed, only to reappear at the worst possible time (such as when your mother in law needs to use the lavatory).

Othon : (storms out of the lavatory, pointing in the general direction of the offensive odour arising from the unflushed turd). "Who was the dirty son of a bitch that left THAT in the toilet?"

Liz : (shrugs) "No idea what you are talking about. I had a number two, but I didn't just leave it in there. I flushed it"

Othon : "Either you're full of shit (figuratively AND literally) and you don't know how to flush a fucking toilet, or this is just another one of your post-flush surprises. Either way, I am not impressed. My shit does what it is meant to. Why can't yours? Get rid of it!".

Post-flush surprise by Macbeth the Wonderslave December 3, 2009