The possible end result of eating the shells from sunflower seeds. Normally, when a person eats sunflower seeds they crack the shell first and then eat the seed inside. Due to the shells exterior, after digestion, a person may end up with a pokey turd.
Hey, did you hear about what happened to Joe after he ate all those sunflower seeds whole, without cracking the shell first? Well, he ended up having a 'Pokey Turd'