I have a friend that lives in Reno, and she has 2 Chi.
The male Peewee has the same problem and when she told me I really did not believe her until now that I'm reading you guys have the same thing going on with your Yorkies...LOL
She said that Peewee backs up his butt on a bush and even puts his back leg's on the bush and poops on the bush
....then takes off running as if the poop was chasing him.
One time a small poop got stuck on him and he cried loud as if someone had hurt him, scared the poop out of Rose she thought something had bit him.....but no Peewee just had poop stuck to his butt