Sounds like the start of a nice Roald Dahl story:
“Haven’t you seen, haven’t you heard
The story of the terrifically toxic turd?
It all began one windy Spring night
On an outward-bound British Airways flight.
High up in the air, that plane turned to hell
On account of the terrible, terrible smell…
The Pilot went back to find the toilet seething,
The passengers looking pained, hardly breathing,
All straight-faced, with not even one blush
To show who’d dropped the bomb that wouldn’t flush!….”