Unless he is fully awake, he is actually urinating in his sleep, which reinforces the bedwetting instead of correcting the sleep disorder . If the signal is still there, have him urinate, and praise him for proper urination. This practice takes about 2 minutes when you are doing the daytime routine. Do it as often as possible. Give him extra liquids to produce frequent bladder signals for more rehearsals.
Repetition is one of the strongest learning tools of behavior modification programs.
Identify one of the last bladder signals of the day and expand this exercise by doing the run to the bathroom five times in a row, holding off urination until the last run. This will take about 5 minutes. Sleeping through the night will evolve naturally on its own. Establishing arousability is what prevents bedwetting. And the sooner you do that, the better.