bowl blaster 

An extremely loud, smelly fart. It doesn't necessarily have to be done on the toilet bowl.

I just had some Mexican food, so you know I'm going to have a bowl blaster soon!

bowl blaster by pentozali August 28, 2006

horizontal bowl blaster 

A term used when one evacuates their bowels in a particularly furious manner, and in doing so gets fecal matter UNDERNEATH the toilet seat.

Man... Rufus just unleashed the horizontal bowl blaster and completely ravaged your toilet.

horizontal bowl blaster by Grubba November 2, 2003