Our 9-year-old son still bed-wets.
The problem is that he is an extremely heavy sleeper; when he needs to pee, he does not wake up - even manually trying to wake him up (either to try and pee preventively in the middle of the night, or to deal with 'accident' after-effects) is a major undertaking; it may take 5 minutes of effort to rouse him awake (this only applies during the night). This heavy sleepiness is not in any way correlated to him not getting enough sleep or rest - it is the same no matter if he slept more or less than average the previous days/weeks.
Sometimes he wakes up after peeing himself, but not 100% of time, and not always right away.
We have tried the following approaches, none of which seems to have any permanent effect at all:
Physical approaches to reduce the need to pee overnight:
Reducing liquid intake before bed (and enforcing at least 30-60 minutes since last drink before bedtime).
Requirement to pee before going to bed (ideally, twice if he is going to bed late enough).
Eliminating pee-inducing food/drink during supper (e.g. no watermelon etc., no high sodium food) - plain water and plain food.
All 3 of these helped to a small degree, in that he makes it through some rare nights without peeing himself. But that only helps in less than 30% of nights, even when applied 100% consistently daily.
Psychological approaches
We tried the usual stuff - praise for waking up dry, a prospect of a meaningful prize if he lasts a week or 2 without wetting the bed, etc.). He also has an aspirational example of a younger sister, who was waking up to pee at night since ~ 5 years old reliably - and we are always careful to not shame him by comparing them, but simply show him the benefits of not bed-wetting she is accruing.
These have zero effect (not unexpectedly, as the issue seems to be not psychological - he definitely does not like to or wants to bed-wet. He simply doesn't wake up when he needs to pee).
Physical environment
We tried everything. Sleeping in bed and on the rocking chair (he loves the latter so at times he is permitted). Sleeping in diaper and without diaper. Sleeping in colder and warmer room.
Zero effect from any condition changes.
Waking him up in the middle of the night to pee, on a schedule.
This has a predicted localized effect (if - after 5 minutes of trying to wake him up - he wakes up and goes to pee - he sleeps the rest of the night dry).
However, it also had zero lasting effect - after months of consistently doing this, whenever we do not wake him up at the scheduled time, he would wake up on his own and go pee maybe less than 5% of the nights, at most.
Pertinent information: one of the parents had bed-wetting issues, but - to the best of family recollection - they stopped by 8-9 for sure, and nothing was done to achieve that that we haven't already tried with our son. Whereas our son shows very little sign of improvement by 9, compared to 8,7,5, etc.
His pediatrician is aware of the situation, but did not find any indications of anything worth worrying about from a medical standpoint.
Bed-wetting is not a new issue - there was never a sustained period in his life longer than 4-5 days where he would not bed-wet unless woken up by a parent to pee preemptively.
What else can we try to do to address the issue?