A national organization dedicated to helping people with "shy bladder syndrome" -- a phobia known clinically as paruresis -- will hold a three-day workshop in Baltimore next week. The event will be a chance for sufferers to discuss and, perhaps, to overcome their fear of using public facilities. It's a phobia that causes some people to stay away from concerts, ballgames or other public events and even to avoid jobs in office buildings and other places that afford little privacy. The meeting, July 18-20, will be based at the student union of the University of Maryland, Baltimore. Participants, however, also will use public facilities in an attempt to overcome their fears. This technique has been used successfully to combat other phobias, including fears of flying and speaking in public. For registration information, call Steven Soifer, the organization's co-founder, at 410-706-7927. There is a fee.