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When someone drops a dookie SO huge or SO hard that it clogs the shitter - even multiple flushes won't "budge the fudge".
Joey ate so much pizza that he left a bowl-buster in there ! I'm gonna need a plunger and two pounds of C-4 to get that mutthafukka outta there !
by Painus inthe anus November 28, 2011
a much larger than normal bowel movement
Man, I must have lost 10 pounds after that bowlbuster!
by A.Nuss November 16, 2011
A massive dump that, with its girth, breaks the toilet bowl.
"John, What are you doing?"
" I have to replace the fucking toilet. Amanda had Indian food last night and laid out a real Bowl Buster."
by Bryan Hodges April 13, 2008