NOt entirely unrelated. took DS for his 3rd EEG recently and one of the staff told me about a poster they had on the wall for the little 'uns to try and explain what would happen. Its still there and shows a cartoon fox in a suit with electrodes stuck to its head. They ran into some trouble trying to explain to a non English speaking Mum and her LO that they weren't actually going to see the fox having an EEG!
I once read a joke about the types of ways in which you poo...also with illustrations. Was rather funny. One of them was the bouncy poo oor something and had someone bouncing up and down on the toilet. This reminded me of that.
We used to encourage ds to go with a small chocolate reward. Now everytime we stop at a service station (which has the 2 essentials of a loo and a sweet counter) he has to use the loo - and annouces proudly to all -- so he can purchase his reward!!