I'd like to share a story.
When I still had a few of my foster kittens, they were running around chasing each other, bouncing off the walls, etc. One was chased into the bathroom, and apparently jumped up on the counter & the back of the toilet. I heard something hit the water in the toilet. I was pretty annoyed, betting it was the kleenex box or something. I go into the bathroom, there was nothing in the toilet. I walk out in the living room and Mickey Blue Eyes (one of the fosters) was licking his back legs and his back. Apparently he was the thing that fell in the toilet.
Serves him right.
Now, there was nothing in the toilet. However if there WAS, the kitten would've stepped in human poop. And i'm going to speak for him when I say he'd rather step in his own poop (as they do in the litter box) than in mine.