You think this kind of stuff is new?
Nanny Smiling broadly at a bathtub being filled in the next room, or her "sightseeing" on long coach rides (hell, nanny overall really)
Privy jokes exist through the series
the Garderobe in L&L
Fool Varence using Privy as punctuation
Constant references to widdling in Maurice
The Long Man
Big Fido's gaseous problem
Moist landing in something soft
Doctrine of signatures and Nobby's love of a certain shaped mushroom
Cohen's love of soft lavatory paper
Living compost in reaperman
References to the odd placement of the trapdoor on trojan horses
and ofcourse without TP (heh) and Errol, we wouldn't have these lovely examples of moving picture entertainment
and thats just off the top of my head. if you think that Terry is somehow above low brow humor, well, thats just a phallusy.