I LOVE shitting at work.
People are always like "Holy CHRIST what IS that?!" and I always shrug and then suggest it was probably one of the smaller secretaries that did it since they were the ones that I saw in there most recently.
The best to do, if you are in a public place and feel kind of vulnerable - is to get rid of everyone around you.
Drop the pants once in the stall, then just start screaming as if you have a hot poker tearing its way out of your belly via the easiest route - your ass.
Claw at the walls, kick the door, take a shoe off and toss it over the stall wall.
Start choking and then make puking sounds too.
I assure you that you will have the place to yourself in seconds flat.