Drop a Nisch
When you really have to take a dump, and for whatever reason you're unable to for an undefined period of time. Dropping a Nisch is the phenomena that occurs as you do the cowboy shuffle to the pot, get the jeans down just in time to drop a nisch. The result is generally a shotgun-like blast into the water below, usually with some collateral damage in the form of water splashing back up your asshole.
After eating those 15 sliders from White Castle I barely made it back to the office. I was prarie-doggin' the whole way to the bathroom, had to Drop a Nisch so bad...