Severe diarrhea in a public restroom. Occurs after you eat at a nasty reseraunt who employs cooks that don't regularly wash their hands. After eating you barely have time to make it to a gas station restroom. Scared to touch your ass to the piss encrusted seat, you rely on your leg muscles to hold you up while on every exhale, a furious river of shit rushes out of your ass. Before your body has gotten rid of the bacteria consumed at the resteraunt your legs and abdominal muscles reach muscle failure and they tremble under the stress.
Sally: "Hey Bob, whats up?"
Bob: "Can't talk now, bitch. I gots the shiverin shits!"