Potty training doesn't apply to night time L. - we are asleep at night (how do you train someone to wake up?).
Bedwetting at night is a BLOOD SUGAR issue and is easily solved.
I went through this with my daughter until she was 7. After testing her for everything, including diabetes, I finally went to see a Naturepath. What she told me worked immediately to stop the problem...
THE PROBLEM: The bladder releases when blood sugar drops so keeping blood sugar levels up is the key to kids sleeping through the night and having more awareness around needing to pee during the day.
THE SOLUTION: Making sure your child is eating a high fat, high protein diet, low sugar diet throughout the day and giving a large high fat/low sugar snack before bed. Water should be given liberally throughout the day and before bed also because dehydration releases the bladder as well (the brain thinks it is starving and blood sugar drops when dehydration sets in).
Bedtime snacks: Cheese with bread or crackers (or just cheese), peanut butter or nut butter with bread or crackers, bean and cheese burrito, fish ~ tuna on toast... what ever you child will eat that is high in fat/protein and low in sugar (make sure your peanut butter is not sweetened).
WATER, WATER, WATER ~ the more water your child can drink the better.
You won't believe how well this works. Start today and he will be all over the bed-wetting and daytime accidents by next week.