The act of having explosive diarrhea in close proximity to a toilet which results in fecal matter splatter on said toilet and nearby areas. Fecal matter splatter resembles the pattern of buckshot or birdshot. Usually associated with Radar Ass or Radar Butt.
Antonym: Immaculate Defecation
Guy 1 - Dude, I had such bad ED that I barely pulled down my pants and BAAMM. Bathroom Buckshot.
Guy 2 - Nasty, good thing we are at White Castle.