In a scene of my novel, I have a teenage boy who, for the first time, is involved in a serious (life or death) violent encounter. He's obviously very shocked. I've currently written that he wets himself as a result. Is this too much / too unpleasant a thought for the reader? Does it help show that the violence itself was an unpleasant experience? Would fainting or vomiting or some other physical reaction convey this better, or be better in terms of reader reaction?