Same as "Whizpop" referring to the BFG series and Roald Dahl books in which the word is used to refer to breaking wind . Whizzpop is a spelling used in the BFG books and newspaper cartoon strips.
BFG drank a bottle of Frobscottle and soon after there was a mighty whizzpop!
Another name for a fart
"Omg, i nearly whizzpopped at school earlier!"