Have you ever seen a real Shit Box? I'm not using the term as an adjective for the cardboard, I'm just relaying the product name. The light-weight portable toilet is for those moments when you get the urge for number two on the road, but don't have access to a proper toilet.
"The box pops up from a convenient 14 inch flat pack to a rigid, reusable, comfortable toilet," the Brown Corporation describes. "Each box comes with ten degradable poo bags."
Just like you wouldn't leave your dog's poop on the side of the road (right?), you shouldn't leave a heap of your own doo either. Instead of scooping, just do your business right in the, er, stool-shaped box to avoid making a mess.