Dr Grant replies: Bed-wetting or nocturnal enuresis is very common and considered normal up to the age of five years old. Some kids, once ‘potty trained’, are dry throughout the night pretty much straight away. Other kids take a lot longer to get there. There are multiple contributing factors such as poor sleep arousal (your child being a very deep sleeper), reduced bladder capacity or an overactive bladder.

You may notice your child also has daytime urinary urgency (if I don’t get there fast enough I will wet myself), frequency of urination (going more than eight times per day) or even episodes of daytime urinary incontinence.

Two simple things to rule out first are the possibility of a urinary tract infection or chronic constipation as both can cause bedwetting, particularly in a child who was previously dry at night for more than six months.

There are many common misconceptions about the management of bedwetting. Continuing to wear nighttime pull-ups, severe restriction of fluids before bedtime and waking your child during the night to pass urine are three examples of techniques that are not only of no clinical benefit but may perpetuate the problem.

Explain to your son that if he wakes at all during the night, he should be encouraged to go to the toilet before trying to fall back asleep. Explanation, education and reassurance, along with positive reinforcement, are all that is needed for the majority of children. Investigations such as blood tests or scans are not generally required.

I recommend you start with a chart documenting dry nights with a green or gold star, amber when a few drops may have been leaked but the child then woke to pass urine and lastly, wet nights with a red star, as this can be really helpful. Setting weekly goals with your child such as a playdate or trip to a play centre/zoo/museum as a reward is also very important.

Remember, rewards should not be just for dry nights but also for good compliance with agreed behaviour (such as voiding before bedtime, and drinking approximately one litre of fluids slowly and consistently throughout the day rather than just in the evening time).

Obviously, children should avoid all caffeine-containing drinks — and be wary of too much chocolate, as this also contains caffeine. Teach your son to listen to his bladder and pass urine in a timely fashion, instead of holding for too long. In other words, go when he needs to go, but ideally not more often than every two hours during the daytime.

Bedwetting alarms are a first-line treatment and have very good clinically proven success rates.

If you find your son simply sleeps through the alarm regardless of how high the volume or what sound is used, then I suggest you share a double bed with him for the time being. By doing this, you can get him to wake up as soon as the first few drops of urine are leaked and comfort him. Take him to the bathroom and go back to sharing the bed with him until he is dry for about two weeks straight. By then your job should be done and you can go back to sleeping in your own bed, but continue to use the bed wetting alarm for a few more weeks.

If, after all the above, you find your son did not manage to succeed in conquering his bedwetting, then I suggest you take him to your GP who can refer him to a specialist bedwetting clinic.