Here's a Google search
stun gun urination - Google Search
While the first result says no, many others on that page say yes.
OldSteve, It makes sense that something that powerful may very well cause you to lose control of your bladder. If they are trying to promote stun guns they may downplay that fact. Other articles may be more honest in their assessment of the effects of a stun gun. Thanks for being thorough! It was late and I just read that one article.