I'm sorry to hear this is happening to your young son. I can understand why the school's reaction feels uncomfortably punitive to your family. We have an article on toileting that might help, I'll add a link to it below. It's a little tricky for you to help him at home since this is an issue that he has just at school. But anything you do at home to boost his confidence and help him feel loved and connected will help him in his struggle with this challenge in playschool.
 
The first thing I would suggest is that you get yourselves on a regular schedule of Special Time. Set a "date" with your son for this. I realize he's only three, but it's important for him to have an opportunity to anticipate Special Time, even if you just say, "As soon as we are finished with our snack, we're going to have five minutes of Special Time." Then set a timer or use an external counter like an alarm clock to mark the beginning and the end of the time clearly.
 
When it's Special Time, you tell your son, with warmth and eagerness, "We've got five minutes (or ten, or whatever you've got available) of Special Time and I'll play anything you want." During Special Time, you follow his lead. He gets to be in charge and you follow along with his play with as much warmth and fun as you can muster. When Special Time is done, tell your son how much fun you had playing with him and when the next Special Time can be.
 
As he adjusts to the routine, your son will begin to use Special Time, when he has your full attention and focus, to work on things that are challenging for him, or emotional issues he has no way to verbalize. He will benefit greatly from having these protected bits of your time and he will quickly understand that you won't allow yourself to be distracted until the timer is done. This creates a spot in your relationship where you are ready to welcome whatever it is that's not working for him as far as toileting at playschool goes, or anything else he may need to work on.
 
I'll add a link to our booklet on Special Time and our other Listening to Children tools under the article on toileting. You can also check out our blog for stories from parents who use this approach with their kids in the third link.
 
Having caring and thoughtful parents ready to support him is already a huge advantage for your son. Keep up the good work!
 
Juli
Julianne Idleman
Hand in Hand Program Director
www.handinhandparenting.org