A shitsnesm is when oneshits/sharts, while simultaneously having an orgasm and sneezing at the same time. It is a combination of relief, pain, and pleasure.
Dude, did you see the Shitsnesm John Alex performed this morning, it looked so painful!
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.