Hi Celeste,
I hear your frustration and I'm imagining you are wanting to support your child the best way you can--and it sounds like you're worried about his health. And it sounds like you are wanting to support your own needs for cleanliness, predictability and hygiene in your home--? The best thing I can say first is please be patient. Children are still quite young at age seven, still tender, and they can respond to frustration with shame. I don't think you'd mean to be shaming--yet I can imagine him feeling that way given that it sounds like you think either something is wrong with him or he isn't cooperating. My daughter is six and a half, and she's had the same frequent urination situation. Also wears a diaper at night as she's not aware of when she urinates at night. I haven't been too concerned about the diaper at night, though I have wondered how it will shift. I've spoken with some adults that remember making the transition at 8 or 9--it took that long for them to be able to feel the urge to when they were so deeply asleep. Two things I have learned about this.
One is that it is not uncommon for children to still need to wear diapers to bed at this age. When I talk with other parents about it, I hear that all the time, about how so and so needed diapers until such and such an age--older than our kids. Given this I accept where my daughter's body is now and support her with a diaper. She doesn't have conscious control, and I would not want her to feel bad about herself because of this.
The other is that I recently took her to a Chinese medicine doctor, not just for this, but for this along with some other symptoms that together I was concerned about. He knew immediately what the situation is and has been treating her for about two months. There's been a significant improvement in all of her symptoms, including having more control over urination and not needing to go as often. My experience is that Western medicine has little to offer about this kind of thing so I'm not surprised that your pediatrician wasn't much help--though I do appreciate the accepting attitude. Still she needs a diaper at night--that hasn't changed. I did talk with one mother who told me about a biofeedback product that helps the kids learn when they pee at night, and I am going to look into that soon. Let me know if you want to know about it, and I can pass on that information when I get it. Before going that route, though I wanted my daughter's overall condition to improve, and it definitely has.
I would be interested in hearing from other mamas about the transition at night-time out of diapers for kids age six and older. I'm sure there's a wealth of wisdom out there!
blessings and patience for us all on this mysterious journey,
M.