The feeling of immense well being that arises from taking a big satisfying shit.
I was dying for a turd and had to use the management toilets, it was a whopper, I totally bumgasmed! My turds are always big when I eat muesli.
by boshface May 23, 2011
to have an orgasm 'up the arse'.
my dad gives better bumgasms than your dad does
by chad March 13, 2005