Turtle heading

When you have to take a poo ... Really bad, but don't have access to a bathroom. The poo pokes out of your butthole as you try to sqeeze it back in so you don't shit your pants. Much like the way a turtles head peeks in and out of it's shell. Often you can tell if one is turtle heading because they will walk funny, from the effort it takes to keep from shitting their pants