When you have the absolutely worst case of diarrhea that you feel like
Jeff Daniels did on the toilet in Dumb and Dumber and the pain is too
much to bear.
When you drink too many glasses of milk or some lowdown bastard spikes your food
with laxative or you eat too much spicy food, you'll know for sure you'll get them, and
you'll be on the can for a good long time having the screaming shits.
Diarrhea so bad that the loose stool exiting the anus creates a whistling noise. It should be noted that the noise can range from a low pitched hum all the way to a high pitched scream like a Piccolo Pete firework.