Complete this joke...

[Macdaddy Warsaw]

Rectum! I destroyed 'em!

Similar, I guess, I don't know the joke behind this one either, but I bet they're close.

[HamJam]

[ QUOTE ]
Rectum! Damn near killed 'em!

[/ QUOTE ]

I don't know the joke either but have heard that punchline multiple times.

[pudley4]

Little Johnny had a foul mouth and his teacher always tried to correct him whenever possible. One day the class took a field trip to visit a farm, and Little Johnny and his buddy Billy ran off through the cornfield. The farmer had just finished harvesting the corn, and buddy Billy tripped and fell on a corncob, which got lodged up his butt. Johnny came running back and breathlessly told the teacher: "Teacher, teacher! Buddy Billy fell and got a corncob shoved up his ass!"
Teacher: "Johnny, it's 'rectum'"
Johnny: "Rectum?! Damn near killed 'em"