hi dizzy. your anxiety disorder sounds more like a type of toilet phobia where the person is afraid of a particular feature of toilest. (in your case, that they might flood). this type of toiletphobia - though less common - is definitely shared by other people (though the triggers can be different). for some people, it's ONLY toilets with chains... for others, black cisterns, and so on.

you might find it useful (if you haven't done so already) to check out the uk toilet phobia group (there's a link on the homepage of this site).

best,

baz