i run bedwetting clinic for my job but we wont see children until 7yrs plus as child needs to want to be dry and feel some embarassment to get them dry.
top tips:
ensure he is drinking at least 1.5litres a day, this is the main reason children wet.
avoide fizzy drinks and pure fruit juices occasionally is ok but not in the 2hrs before bedtime.
at bedtime get him to wee, clean his teeth, then wee again.
dont lift hime unless you can be sure he is fully awake and can hold a conversation that he remembers the next day - otherwise all you are doing by lifting and putting on loo is encouraging him to wee whilst asleep.
take out of nappies let him feel the wet sheets - summer is a good time to try as weather is usually nicer to get sheets dry.
If after 6mths no joy leave him for another 6mths before trying again.
if he gets to 6.5yrs and still wetting see your gp or contact school nurse for an appointment at the bedwetting clinic.