A fetish act in which a person who is suffering from diarhea poops on the chest of another person. A third person then takes a "regular" dump on the chest. The turd slides down the trails of diarhea and slightly resembles a log flume.
"That girl I slept with last night had some crazy poop fetish. She wanted me to get another guy and have us give her a Colombian Log Flume."
by Sir Chico September 22, 2009