bitski is synonymous with "bit"(as in small) except it has a 'ski' suffix attached.
(Noun.) The waste produced by a human that had consumed too much spicy foods. It happens to resemble a mocha chip ice-cream soft-serve cone with red sprinkles embedded within it.
Ken: "Hey Billy , you alright in there? You've been on the crapper for two hours now..."
Billy: *groans in pain* "No! Finna finish making this sriracha swirlie!"