Schrodinger's fart 

an ambiguously ominous pressure in one's bowel that is simultaneously flatulence, diarrhea, and a bowel movement until it is released, at which point quantum superposition ends and one must simply hope that they guessed correctly.

It's a good thing I went to the bathroom for that Schrodinger's fart, or else it would have been messy.

Schrodinger's fart by Squeaky Farts January 7, 2021

Shrodinger's fart 

The moments when, feeling the fabric leave your arse cheeks, but it could be either a large fart bubble or a sneaky poo. Unsure if it's fart or shart, it being considered to be simultaneously both fart and shart until your pants are dropped & the remnants observed.

"Oh man, I had way to much Guinness to drink last night. I woke up this morning and had to run to the loo after a Shrodinger's fart"

Shrodinger's fart by ShrodingerFart May 22, 2016