Strawberry jelly — a diagnostic hazard

A sign of increasing age, no doubt, but Merlin has had to subject himself to the tender mercies of the NHS once again. Following on from some symptoms that are not of the kind usually discussed at a polite dinner party, he was given an appointment for an endoscopy.

For those colleagues who have never experienced this particular diagnostic procedure, adequate bowel preparation is essential.

In addition to the senna and Picolax regimen (the exothermic reaction when the latter is placed in water is fun), there is a restricted diet.

For obvious reasons, this must be as low-residue as possible. One of the few food items permitted, other than clear soup or Bovril, is jelly.

On Merlin’s arrival at the endoscopy unit, the receiving nurse asked him about his preparation: “And what did you eat?”

Merlin replied: “Jelly.”

“What flavour jelly?”

At this, Merlin put on his best John McEnroe you-cannot-be-serious voice and replied: “Strawberry jelly, prepared by my wife.”

The nurse then patiently explained that red jelly, such as strawberry or raspberry, is often not digested and can look like blood through the endoscope.

Now, not all pharmacists have the privilege of seeing the inside of their own colons. The endoscopist kindly positioned the monitor so that Merlin could see the full picture. There, in glorious Technicolor, and looking for all the world like smears of blood, was some of Mrs Merlin’s strawberry jelly.

Two points occurred to Merlin. First, in a hungry patient whose entire gastric tract has been cleansed, why is jelly not absorbed rapidly? We here need the advice of a colleague well versed in the physicochemical properties of gels.

Secondly, why did the hospital’s preparation instructions not advise against consuming jellies of a reddish hue that might be mistaken for blood and may even mask real blood during the endoscopy procedure?

The end of the story is that Merlin does not have any nasty disease and will live to fight, and write, another day.