That's actually worse because it would be more likely to clog your drains. Your dude goo would be thicker than urine which is basically just water. If I remember correctly heat such as that from a shower will actually cause it to coagulate more.
I'm sure the urban dictionary link answered your question, but if you didn't go there for whatever reason, it's when you push a turd down your tub drain with your foot.
(And for the record, I didn't actually poop in my shower)