Doodie.
Poop all the way. Poo-poo to be very cute.
Twiddle
Doo doo. 
Poo only if I’m talking specifically about the fecal waste of dogs, and even then, very, very rarely. Poop in referring to human waste in a situation where it won’t do to refer to it as “shit.”
Actually, when not saying shit, I usually just say fecal matter non-discriminately now that I think about it.