Constipation

Alright listen up, genius. The joke is that the movie is called "Constipation" which means you can't poop. And it hasn't "come out" yet. Get it? Like when you're constipated and you can't get your poop to come out? You probably eat too much fiber, which is why you didn't get the joke in the first place. Everyone knows the less fiber you eat, the smarter you are.