Harry Potter, it turns out, was a bed wetter.

Leading paediatrician, Dr Mandy Fletcher, helps children of all ages who wet the bed. And she says that now that kids are finding out Harry Potter also wet the bed, a fun fact revealed in the latest Harry Potter book, is very reassuring.

Bed wetting – otherwise known as nocturnal enuresis – becomes a problem when there’s been more than two accidents a week for more than three months in a child that’s five years or older.

“I have quite a few teenage patients, of course the prevalence decreases as age increases, so about 20 per cent of five-year-olds will wet the bed, 10 per cent of 10-year-olds, and about 0.5 to 2 per cent of 15-year-olds,” said Dr Fletcher.

It’s important if parents are worried about their child’s bed wetting to see their GP in the first instance, then they can decide if they need to come and see a paediatrician.

“When we look at bed wetting we are kind of divided up into two groups – those that have always wet the bed are what we call primary bed wetters, and secondary – they’ve been dry for at least six months and now suddenly for some reason they’ve started to wet the bed again,” said Dr Fletcher.

“Obviously in those cases we’re more likely to be find an organic cause or a psychological cause for that.

“It’s important to look at family history because often genetics play a big role surprisingly in bed wetting and there’s usually one parent that had some trouble.”

"There’s usually one parent that had some trouble." Image via iStock.

The Sydney paediatrician says the children that feel most venerable are those of school age that are worried they are going to wet the bed when they are away on school camps.

For some children, it's a comfort that JK Rowling's lead character had similar problems. Rowling reveals the new fact about Harry in her latest book, Harry Potter and the Cursed Child during one of adult Harry's flashbacks to his early childhood.

"The world’s most famous wizard had bed wetting problems and I think it’s reassuring for some of my teenage patients," Dr Fletcher says.

The 38-year-old says it's important to rule out constipation and examine fluid intake at night - especially with older children who are drinking gallons before bedtime.

"The good thing is there is a lot of things we can do to help children who do bed wet, and we do have an 80 per cent success rate with using alarms like a bell and pad - it’s a little insert that goes into the underwear and the moment that there’s urine there, the alarm goes off."

The alarm system is apparently "very effective" because it teaches children how to hold the urine in their bladder, however, the paediatrician says the biggest reason patients relapse is because children stop using the device too quickly.

Dr Fletcher says bed wetters and their family members need a lot of reassurance because of the social stigma of bed wetting.

"They feel shameful that this is happening, but they really need to know that it’s not their fault and there is help out there.

"Sometimes children need to go to a psychologist just to help with their self-esteem...

"But it’s more the secondary [cases] that have been dry for a while that there is some psychological stress - and with those children, we find that during the school holidays period they are hardly any if any accidents, and then when they go back to school, the night before school, they tend to occur more frequently," she said.

The longer the bed-wetting continues the more likely children will feel embarrassed and frustrated.

"We find bed-wetting inhibits social activities and has a negative effect on a child’s confidence and self-esteem, therefore seeking medical advice sooner is recommended. Additionally, throughout this process it is important to reassure your child and ensure they feel supported."

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