I was asked about this in one of the comments, and I found that it is difficult to find my answer unless you already know where to look. So, I’m repeating myself here as a post to make it easier for everyone to find this information. We just started this blog about a month ago, and I’m still playing around with it to see how it all works. Below is my answer to Jennifer, one of our Moms here at Meyer Pediatrics who asked me about children who are late to get dry at night (and have never been dry before).
OK, at age 4, about 80% of all kids are dry at night. Those that aren’t are the “late” group, and they will slowly become dry over the next 10 or so years, at the rate of about 10% per year. SO, at 5 years old, about 90% of them are still wetting, and at 6 about 80% and so on. It’s NOT laziness or anything like that. It’s because, for reasons unknown to me, these kids are slow to get the night-time rise in a hormone called ADH (Anti-Diuretic Hormone, which is naturally secreted by our brains) that those of us who stay dry get. Ultimately, just about all of them WILL get this night-time surge and they will become dry.
There ARE rare other causes of night-time wetting (and I am ONLY describing kids who have ALWAYS wet the bed here, not kids who WERE dry and then started wetting later). At any rate, these kids should have a good physical exam one time to be sure that there is nothing else causing the enuresis (the medical term for night-time wetting) as there are several treatments available, at least for sporadic use, such as when your child wants to have a spend-the-night party without others finding out. In these cases, there is a prescription medication called DDAVP that is a chewable pill taken before bedtime that in over 80% of cases is successfully able to keep a child dry for that night.
Therefore, to answer your question, I would recommend the pullups until they aren’t needed anymore, whatever age that might happen to be. My patient who was the latest to get permanently dry was about 16 or 17. For the routine changeover from pull-ups to underwear, “big kid” underwear should be a reward, NOT an inducement. They should only be allowed to wear “big girl panties” when they can go a whole week without wetting.