Not sure if anyone is interested, but as an engineer.
I built a ‘replica’ latex female bum a few years back for a customer (don’t even begin to ask how this all happened)…
This latex, full sized ‘bum’ had a battery powered piston inside that pushed out the ass anything you pre-loaded.
So basically… you could directly shit into the top of the rig (it sat across the top of a bathtub) and then you pressed the start button.
After a random amount of time (you could set the timer), it would suddenly expel shit out of the ass just like the real thing.
It also had a pump that allowed you to pump fresh piss out of the peehole in the vagina.
It was a hollow cast, so if you filled that void with warm water, you then got warm piss and poo.
Anyone interested? I still have the mould!
These things ain’t cheap to build (I seem to remember the latex and linear actuator cost £500 on their own), but it does give you a female ass that will deliver when you need it too!