TopicTrouble Urinating in Public Restrooms?
The problem is not urological but psychological. Just Drinking Water as many people have phobias, for example a fear of heights or stage freight or extreme shyness, some people have a fear of urinating in public places. If the fear is strong enough, they may tense up enough that the sphincter muscles at the back of the bladder won't relax and won't let them relieve themselves.
If the problem is relatively mild, there are a number of approaches you can take. One is to use a stall or perhaps a family restroom where there is more privacy. Another is to just relax by perhaps going to the restroom before there is too much pressure and telling yourself if it doesn't work you can always try again later. You also should fully relieve yourself at home before going out. Drink sparingly when not at home and avoid beverages like coffee, beer, and other forms of alcohol.
If you still have a significant problem, certainly talk to your doctor. There are psychological treatments such as cognitive-behavioral therapy, relaxation therapy, and biofeedback bladder training. There are also some medical treatments such as the antidepressant drug Paxil and tamsulosin, an alpha-blocker.