Dd was daignosed as having an irritable bladder (AKA I think as an overactive bladder). It seems that somehow the messages don't go from bladder to brain properly. She may genuinely not recognise the physical urge to wee. At the same time, her bladder can trigger to empty itself even if it is not full. And there is no build-up, no dawning awareness of an increasing urge, just a sudden need and seconds later - wee.
The paed said that it was a matter of maturity. Physical or emotional. Either things would eventually sort themselves out and she would be just like anyone else (which might not be until puberty, there's no knowing) or she would develop the emotional maturity to deal with the stuation, knowing that she has to go whether or not she feels the urge. She would also have to become sufficiently aware of herself that she could deal with distraction as well. Which might also not be until puberty, or even later!
Dd could wet herslef several times a day, to any degree. She would rarely admit to it, so we were dependant upon the teachers noticing that she was wet. Of course, there's smell, and chaffing as well, to worry about. Often you could see her jiggling about, obvioulsy needing to wee, but totally unaware of herself. Sometimes there would be no warning.
The norm would be smelly knickers every night (ie she had leaked during the day, though not had a big wee in her knickers), with a bigger accident a couple of times a week. Sometimes there would be good phases of 2-3weeks, where she was dry all day several times a week, but just as often there would be bad phases when she was properly wetting at least once a day every day. She would often complain of sharp needle-like pain on weeing, or during the night, and this would often be before or during a bad phase, but tests never showed anything conclusive.
She had an ultrasound which confirmed that eeverything was structurally OK, and that she was emptying her bladder completely.
The medicine that the paed wanted to prescribe, Oxybutinin, is a fairly strong drug, with potential short-term and long-term side effects. It's been in use for many years, and is fairly safe, but, nonetheless we were not keen to put dd on long-term medication for something that could possibly be managed. The school was very supportive and understanding. (Dd is in an infant school, where the children are younger and closer to babyhood. Had she been in a primary school, or older, at junior school, it would have been a different matter.) So we held off using it for about 6m, until dd's teacher reported that other children were begining to notice that she wet herself very often.
Dd has been on the medication since spring. We had 6w of distressing side-effects: her lips were so dry that they cracked an bled, but worse was the most appalling behaviour you could imagine. It also gave her terrible reflux, 5 or 6 times a day, whcih frightened her as she thought she was going to vomit. All these side effects are warned about in the medication leaflet.
It took a couple of months to find the right dose. Fortunately it is just above minimum dose. The side effects cleared up and changing from liquid medication to tablets stopped the reflux. Though she still refluxes if she takes it on an empty stomach.
Her wetting is not 100% under control, but is now at a level that most people would consider acceptable in a 6yo. We felt it was tolerable, and possibly also important that dd be aware that there is a problem she needs to learn to deal with. She still needs reminding to go to the toilet, still denies accidents, but her control is much better. And she very rarely gets the pains that we thought were UTIs.
We also think that, if it's completely controlled, how will we know when to take her off the medication? If we just give it a few months and then try without the medication, and find that she still wets, then we will have to go through the side-effects again. Which nobody wants!
So that's where we are.
BTW, dd is still in night nappies, and the paed warned us not to expect her to be dry. But in the last couple of months we find that, if we lift her at bedtime, she is often dry in the mornign.
HTH.