The level of ease (or difficulty) of a particular item to be ingested orally and successfully passed via bowel movement.
"Be careful, Mervin. Those Walmart hotlinks have a low shitability score."
"Too late, Elroy. I'm fartin' blood over here!"
(also spelled turdle dumpkin) a massive bowel movement resembling the shape of a turtle.
"Hurry up, Elroy! Brisco County Jr. is about to start!"
"Sorry, Mervin. I was pushing out a turtle dumpkin."