Success at last!
With thanks to Trevor Lister for supplying the words.
(This one will run and run...)

The GASTRO-ENT... (Dave Waddington)
(To the tune of Old Peculier by Keith Marsden)

Some people go on holiday and drink their fill of booze, sir
Some people book a package tour and some they book a cruise, sir
Whate'er the type of holiday, whate'er your ship or flight is
There'll always be one passenger with Gastro-enteritis

(Chorus:)
The gastro-ent, the gastro-ent, the gastro-enteritis
The trots, the runs, the Gippy tums:
The Gastro-enteritis...

Some people fly with QANTAS (AIR) and some fly with SABINA
Some fly to France, some Istanbul, and some fly to Medina.
Whate'er the place you're going to, whate'er your place to alight is
There'll always be one passenger with Gastro-enteritis

When drinking water overseas, first always you should boil it,
Make certain that the room you book has got an ensuite toilet;
You'll stand for hours in corridors in 'jamas or in nighties
If the poor sod locked in the bog has gastro-enteritis.

Don't eat the seafood in Korea, nor the mutton in Namibia
Avoid the wine in Austria and everything in Libya
'Cos whether you're on tropic shores or where the Northern Light is
There'll always be one passenger with gastro-enteritis.

Avoid those greasy foreign foods, especially those with meat, sir
And stick to good old British grub, like fish and chips and pizza
'Cos whether you're on foreign shores, or whether you're on Blighty's
You could be that one passenger with gastro-enteritis.