Yes, one of the side efects is less bedwetting, so it very possibly could affect a child who wets his pants. Thats why they say to monitor urine output with Strat as it somehow affects the kindeys I think.
Ds started taking strattera in 5th grade when a urologist started him on DDAVP because he was still wetting his pants. It got much better in the next six months and by the time he started middle school, it had gone from almost every day to maybe once a week and that was usually when he sat and played computer games and just didn't get up to use the bathroom. He has been on strattera ever since and we kept him on it when he started the patch.