First off, What exactly happens to the food that is passing through body that makes it turn into shit?
And, Is it possible to turn food into shit, without having to eat it?
Eliminate the middle man, so to speak?
It’s been done. Ain’t the new millennium grand? 
Daniel
My mum used to do it when I was a kid. Just give her half an hour in the kitchen, and you’ll see. :grin
Damn smiley code. Forgot which board I was on.
Shit also includes a lot of bacteria, alive and dead, and the remains of red blood cells, among other things. So you’d have to add stuff to the food as well as take stuff away.