In our home, everything we do is an opportunity to learn something new or to make a new connection to something familiar, allowing each of us to gradually build on our unique understanding of the world. That learning can be inspired by something as personal as how one prefers to address washroom practices. What shape that learning takes depends on how one addresses the experience.
Did you realize that King Henry the VIII had a Groom of the Stool? I didn't. But I was thinking about my son's practices when he was younger, after thinking about something written here, after thinking about this question about how bathroom practices are part of unschooling, leading me to wonder if royalty at one point had someone looking after these personal needs, which further led me to look it up and find a little piece of writing on a site called Historic UK about the job of Groom of the Stool. This led me to remember a book Doug, Ethan and I read at night together for a while called "Worst Jobs in History," and reflect briefly on some of the ways our simple bodily functions and the byproducts of those functions have been made into jobs of some sort, somehow.
Knowing that Henry VIII had a Groom of the Stool or that urine was used to tan hides isn't most important, however. Making room for learning of any kind to happen naturally at any time, is crucial, I think, to successful unschooling and successful life-long learning. The parent from the original question has an opportunity to learn more about her son. Her son, if given room to do so, has an opportunity to learn more about himself. Where that learning will take them depends on how open they are to the many opportunities that initial position offers.
Twenty years from now, the boy might be a therapist, helping others with similar issues. He might have a son or daughter of his own facing similar challenges. He might have a friend of a friend of a friend with questions. He might read a book or watch a program that prompts him to draw on his own experiences, allowing him make a unique link in the chain of his own understanding of the world. Or, he might never think of it directly again. But how this parent and child move forward will influence future learning in some subtle or greater way because that's how we build our model of the world--one humble, or profound, or everything-in-between experience at a time. The more we can be open to that, the bigger and more interconnected our model of the world will become.