Waterpoo
A diarrhea in which the feces is so liquified that it has all the properties, save color, of water. It flows so quickly and uncontrollably that it is hardly noticeable when leaving the anus, and may look like urine once in the toilet.
Oh God, I think I ate too much of those buffalo wings. I can't control it anymore. It's so wet, I think it's waterpoo!