Shit Tremors
The series of rank farts leading up to a huge shit, much like the tremors leading up to the eruption of a volcano.
Guy1: Dude, that smells horrible. What did you eat, this has been going on for a few hours.
Guy2: I feel like I'm going to erupt
Guy1: Oh, you must have shit tremors
Guy2: I feel like I'm going to erupt
Guy1: Oh, you must have shit tremors