A fecal foreplay game that involves the act of pooping into another persons anus; preferably of a solid nature. The goal is to pass the poo as many times possible without letting it slip out and hit the ground.
I met this girl on craigslist who had a serious poop fetish. We played a few games of Sphincter Shit Swap before getting into grimy, unprotected anal sex. I beat her 12-5.