All 3 of my kids are/were bedwetters. Pediatrician said that often it is genetic (I did it when I was a kid until about 4 or 5). My kids are the deepest sleepers! We joke that a group of elephants could thunder through their room and they wouldn’t wake up!
What worked for us: an alarm. We had tried the other things: waking them to go to the bathroom, limiting drinks before dinner, etc. I know that they would probably outgrow it, but my oldest was getting frustrated (she was 7 I think), so we decided to buy an alarm. It clips onto the underwear and goes off at the first sign of wetness. The first week was like having a newborn in the house – the alarm went off several times in the night, and she was still half-asleep so basically I got up, got her up, helped her get to the bathroom, changed her clothes, sent her back to bed (we had waterproof pads with a towel on top on the bed, so we just had to swap out the pad/towel). Eventually, we got there.
Now my son uses it (he’s almost there – mostly dry but a few nights here and there when he’s really tired), and eventually my youngest will need to also. The alarm was pricey, but I figure it was a good investment since we obviously have that issue with all the kids.
HTH,
Tanya