Okay, mamas. Why don't we try exercising some of our compassion toward mama, too? It's so easy to criticize and pretend we've never done or said anything wrong to our kids. I can understand the frustration S. is feeling if she feels that her son is doing this on purpose and if she didn't know that this could be a physical problem. And I know from experience what it's like not to have had a very good parenting example in my own life to follow and having to learn it all by myself, from books and from my husband's much better childhood experience. Let's lift one another up as parents and help each other out instead of belittling. Sure, if you see a need to be candid with your advice, be candid, but have some grace and respect, too. Good heavens. After all, if a parent was doing something really wrong, wouldn't you want her to have a place to go where the mom could firmly but lovingly give her advice and correction. The way you're all going on, I know I'd be hesitant to ever come back.
S., my two younger brothers had this problem growing up and I can tell you from the bigger sister's perspective that they were NOT doing it on purpose, they weren't even being lazy. They wanted desperately to stop, found the problem embarrassing, wanted to avoid the punishment and desperation of my parents (who, like you, didn't know for a little while that it was a physical problem and thought they were just too busy playing to stop and go to the bathroom). They often would try to hide it from my parents, clean it up themselves, hide the underwear or the poo. So, I definitely echo the moms who've said not to turn this into a traumatic thing for your son. He's likely not doing it on purpose. With my brothers, it turned out that maybe in the beginning, they'd held it so they could keep playing... and they'd done that so often that they got backed up... pretty major blockage that made it difficult for them to even feel when they had to go until it was too late. My mom had to give them enemas for a while, after seeing a doctor, to treat the blockage. So, I'd suggest taking him to a doctor and asking about this.
Also, I'd suggest a book called "Grace-based Parenting" by Dr. Tim Kimmel that I just read and that talks a lot about our perspective as parents, raising children who are prone to sin, just like we are. So that when your son does make a wrong decision down the road, as he is certain to do (as we all have), you'll be prepared with the grace to come alongside him in life rather than having him hide everything from you. After all, those difficult moments in our children's lives are what we're REALLY here for as parents. I got it from the library, so see if you can check it out! :)
Blessings,
R.