How to get 5 year old son to do a better job wiping his butt after going poop?

My youngest is 5 and was potty trained shortly after his second birthday. While none of my boys were difficult to potty train, he took the longest (we started a couple weeks before his 2nd birthday) and probably would still be in diapers if we did not push the issue. He never cared about having a dirty diaper, which we always thought was so strange because he has some mild sensory issues when it comes to other things and generally does not like being dirty. Poop and pee never bothered him though.He has had issues wiping for a while now but it is becoming obvious he is not even trying anymore. I am pretty sure he just pulls his pants up, washes his hands, and runs out the door because it is that bad. His underwear is stained and I have made him go change and shower because he smells that awful. I can catch it if we are home but he often comes home to use the bathroom and then runs back out the door to go play at the park so I don't always catch him. I also can't do anything if this happens at school. His school doesn't allow a change of clothes. If a kid has an accident they need to be signed out of school and taken home, so I am not sure what they would do in this case. He never pooped at school last year but there is always a chance of running into aj emergency situation.Is there anything we can do to fix this? Much like my middle son this one does not care about punishments or rewards. via /r/Parenting https://ift.tt/2BkYbHc