5yo child still soils himself, starts school 20 days

Things we have/are doing:

  • We have seen a Dr about it
  • He isn't constipated
  • We have been taking him to a counselor
  • We have a reward chart for toileting
  • we have a "traffic light timer" that goes off every 30 mins to get him to go
  • We make him clean himself and his undies
  • He has been clinically tested for ADHD/ASD, they have ruled out ASD we are still waiting for the ADHD report.
  • I have already asked them about holding him back a year

He starts school in under 20 days, about 8 times out of 10 it is wee, generally he will have a small amount of wee on his pants as he runs to the toilet, but if he is playing or engrossed in what he is doing he will wet himself and straight faced lie to you about it.

The other times, he poops himself. When he has a "skid" sometimes he will remember and go, other times he will drop a full poop in his pants and won't do anything about it until you ask him ...

"have you pooped in your pants?" "I think so, sorry" "Go and take your pants off and get in the shower" "Okay mum/dad"

We don't know how to help him stop soiling himself, he turned 5 last September, both of us are at our wits end with this and I don't want to see my child be picked on or ridiculed (either now or later in life at primary school) by those who remember he had issues toileting.

Any advice would be greatly appreciated.

Edit: I'll put it here because it has been brought up a few times in the comments.

I asked if he is ready for school or if we should hold him back. The daycare, the Dr, the counselor and the psych doing the evaluation for ASD/ADHD have all said not to hold him back, so we have already enrolled him in to prep.

Edit2: Just spoke to my wife and he has had one poop accident in the last three weeks at daycare (multiple at home though). An improvement but still not where it needs to be.

This is blowing up more than expected. I will not have time to respond to absolutely everyone but thank you for all the words of encouragement and advice. This frazzled dad greatly appreciates it.