it was the fact that I asked the woman if she had a disability and she said no..I would have apologised for seeming rude if she had.
Before I injured my knee, I had an 'invisible' disability myself, so I do know where you are coming from with that.
As for the comment about 'people moaning about someone going for a piss' is a bit harsh. Why should I have to embarass myself in public because somebody is inconsiderate??