When you have diarrhea and before you can flush you puke in the bowl to make a freshbatch of split pea poop.
My friend Jake repeatedly cooked a leftover lasagna multiple times in the oven which left him looking at the wrong side of a serving of split pea poop.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.