8 year old grandson bowel accidents

We dont know what to do next.  My 8 yr old grandson continues and has been having bowel movements in his pants.  He wont tell anybody and will remain in his clothes for hours and not seem to care.  He does this at school, at home, while visiting friends - anywhere...anytime.  We have tried the concerned parents and trying to reason with him and tried punishing him.  He does not appear to be constipated - but fear that he is just to busy to stop what he is doing, or too lazy to take the time to go in and use the restroom.  We are becoming extremely frustrated.  He also urinates from time to time expecially when nervous, things like the hospital visit.  Please help us with an idea.  

[Kevin Kennedy, Ph.D.]

Has he ever been completely toilet trained or has this been a chronic problem? He definitely should be evaluated medically - don't assume that he is not constipated simply because he has bowel movements. His bowels may be impacted - if so, this would result in encopresis. If all is OK medically, schedule times for him to sit on the toilet, and establish a reward system for him whereby he is rewarded each day he stays clean and dry. You might, for example, make his viewing of a favored television show contingent on staying clean and dry.