Thanks for sharing this information.  I've never heard of "shy bladder syndrome" but when I was in about grade 2 or 3 I remember going to the bathroom and a girl in the next stall commenting, "You pee loud".  I always made sure I went during class when no one was in the bathroom, after that. 

I grew out of it, but it's amazing how words that come out of people's mouths tend to stick in minds.  It's all in how you take it. 

Good luck in your quest to overcome it!