When you clearly need to go #2, and every passing moment prior to doing so results in a steady stream of heinous farts.
**rapid gross farting noises**
Rachel: Ooh Gary, these are awful. What's going on back there?
Gary: I think last nights burrito bonanza left me with a shatty cathy on deck. Shes willing to talk, give up known ass-ociates. I'm gonna go get her confession"
Rachel: dont forget the poop knife