while one is holding back a hefty bowel movement another party sneaks up to the "Beholder" and tickles them. Thus expelling any form whether it be solid or liquid, or that nasty in between, into the tickle-victim had into his or her pants
"Dude, i just got rickled! Turn the car around, NOW!"
"Rickle me once, shame on you. Rickle me twice, thats alot of poo."