Flock of sparrows hitting a windmill
This is the sound made when the brown hail from your anus hits the porcelain of the toilet.
"That vindaloo from last night sounded like a flock of sparrows hitting a windmill this morning, and it left my arse like 12 guage birdshot, I'm telling you!" Winston Churchill the day after meeting Queen Elizabeth the 2nd for the first time over a Ruby Murray.