(There are different words to describe this kind of phobia: Shy Bladder, Paruresis, Parcopresis. It must make daily life very awkward, although if you have used a public toilet in the UK you can understand people's alarm and as for France - well I'll admit it, I'm very afraid of French public loos - I can't go if it's one of those elephant's feet thingies. And let's face it, in America they have a phobia about the word toilet.)