Pediatricians have been studying bed wetting or nocturnal enuresis for a century and we have no answers except it tends to run in families. Most boys stop in puberty if not sooner. There are medications to use for the condition but are only symptom relief for camps, overnights etc...but not a cure.
Do your best to be reassuring, provide comfort eg rubber sheets on the bed or double make the bed for easy stripping in the night if he wakes up to do it.
It will stop; however, if he wets day and night (diurnal enuresis) that is a medical issue. Ask your pediatrician what she thinks about his condition.
Best wishes to him and you.
Wayne Yankus, MD, FAAP
expert panelist: pediatrics