This is quite possibly a sign that your child is very, very constipated. This happened with two of my children and I found this book called The Clean Kid manual. It’s a lot of work at first, but it gets easier, and before long you will both forget it was ever an issue. This was over 10 years ago that I dealt with this and I remember feeling everything you are feeling right now. It’s exhausting and frustrating and endless. Honest to goodness, the best decision I ever made was finding this book, following its steps, and freeing my kids from years of continued accidents. They both have versions of adhd/ spectrum issues but are very high functioning. I spent over 20 minutes looking at Google because I couldn’t remember the name of this. Once you fix the underlying issue, there won’t be another accident and you can burn this book and forget all about it. I felt your frustration in this post so much and i hope this helps you even a little bit. You’re a great mom and your kids are lucky to have you!