look up any word, like kappa:
 
4.
faecal matter in one of its more fluid states, such as diarrhoea
her sheets were covered in bumsauce
by Love February 09, 2005
 
1.
A total bummer. Something super lame.
Oh damn little laxer hitting mad pipe. Total bum sauce man.
by superkoolaid17 April 23, 2010
 
2.
The slightly moist feeling between one's buttocks, specially around the anus generally felt on a hot day, after a day of heavy bum burping or after exercise. Bumsauce is not mearly sweat but actual secretion from the bum and is normally quite smelly. Also called sebum.
Note: this is NOT the same as the squits.
My goodness Mavis, you've got quite a beefy arse this evening. Best you wipe off the bumsauce with your knickers before I go down on you.
by Steven D November 19, 2006
 
3.
Major digestive issues also known as diarrhea.
Dude 1 – Man I got wicked Bum Sauce!

Dude 2 – Well fuck man that’s what you get for eating pizza out of the trash! God go buy a cookbook!
by Somecrazyfemmegirl September 06, 2006