My preview DVD doesn't have credits so I don't know who it is doing the voiceover. An actor probably, making a bit of extra cash between jobs. I wonder if she read the script through before agreeing to it? This might not be her proudest work. Perhaps she thought her television career was going to be all about costume dramas – nice frocks, the crunch of carriage wheels on gravel, handsome men in tight breeches galloping over the fields towards country houses, swooning, heaving, memorable lines. Instead she's reading this: "Threadworm eggs are laid around the anus, causing intense itching. When children scratch the eggs, the eggs stick to their fingers, and can then be passed to other people or objects around the house."

Threadworms are nocturnal parasites, and live you know where. At night they slither out to lay their eggs, which is what causes the aforementioned itchiness. Enterobius vermicularis is their latin name. Mmmm, vermicelli.

Then there's Campylobacter, which may look like a worm, but is actually bacteria, the most common cause of food poisoning and especially prevalent during the barbecue season. The Embarrassing Bodies docs are telling some kids about them, as if it were a children's story. Campylobacter causes violent diarrhea, Professor Val Edwards-Jones tells them. "Some people say it pebble-dashes the toilet because it's so explosive. Fancy your poo coming out that quick! Aghh!"

Pebble dash, like the outside of Mrs Duffy's house. Perhaps Gordon had a touch of the Campylobacters. Now he's going down the toilet.

Anyway, I'm sure this is all a good idea, getting rid of the stigma of these horrible things, and hopefully some of the horrible things themselves. I'm just not sure I want to be involved. I don't feel I need to know when little Emily last went for a poo. Nor do I want to see, on a scan, what stayed inside her. It may look like fog, but that's not fooling anyone, it's poo. And poo is something I don't want to see on the telly. It's important to Emily, I know, but tell the GP about it, not me. That's what they are for. Thank you.