After a few days on a .2 mg dose of DDAVP, I noticed that all it did was make less pee at each accident. It was an improvement but not the one I hoped for. I called my consultant pharmacist who suggested increasing the dose to .4 mg then .6 mg if needed. Looks like the .4 mg dose will be successful. After a week David's been dry all night, except for one morning his "little accident" woke him up. He got up and went to the bathroom. He's always slept totally unaffected by a wet bed. Not me though. I have always been on guard for a wet bed with one eye open. He won't let me layer the bed or put on any kind of training pants. I tried to stay awake longer than him to at least layer a fleece blanket beneath him to keep the wetness off the bed. He wouldn't get out of bed if I woke him in the early morning to take him the the bathroom. He's a heavy sleeper. He has never been motivated to do behavioral approaches. So we'll stick with the oral DDAVP for a while limiting fluids in the evening. I have also tried observing if the avoidance of bad foods would help, but I can't always control him. I'm glad we did the ultrasound, so I know we aren't medicating some kind of anatomic problem. I just wished I knew what really caused bed wetting.