Doctors have been left stumped by an “extremely rare” medical condition that has caused a schoolgirl to hiccup constantly for more than two months.

Emily Marsh, 13, from Wallington, has been hiccuping every two seconds since January, with health experts still baffled as to what is causing the problem.

The teenager is one of only a handful of young people known to have had sustained chronic hiccups.

Despite a string of tests doctors still have no idea how to treat the Stanley Park High School pupil, who can only manage half a day at school because the condition is not only painful but exhausting.

The hiccups – which started as Emily walked to a maths lesson nine weeks ago – are an involuntary contraction of the diaphragm, and only stop when she is in a deep sleep.

Her mum, Cathy Barrett, 45, said: “Absolutely nothing has worked. We have tried hypnotherapy and osteopathy but we are now completely running out of ideas.

“Emily takes it all in her stride. She’s just got to the stage where she’s fed up and wants them to go. I can understand – if you have hiccups for 10 to 15 minutes it’s horrible.

“We believe that someone somewhere must be able to help or come up with a solution.”

Emily said she had tried out nearly every known home remedy.

She said: “I have tried everything – even a spoonful of vinegar. That was horrible – I refused to do it again.

“I’ve tried drinking backwards, holding my breath and people at school have been trying to scare me a lot.”

Dr Ritu Handa, the paediatric consultant looking after Emily at Queen Mary’s Children Hospital at St Helier Hospital, said they had tried a string of tests on Emily including an MRI scan, blood tests and extensive assessments of her stomach.

However, all the tests have proved inconclusive. Other medical problems have been known to cause chronic hiccuping, but doctors have so far been unable to find anything wrong with Emily and have ruled out serious medical conditions.

Dr Handa said: “This condition is very rare and it is frustrating for Emily and her family. We are doing everything we can, working with our colleagues and closely with the family, to try to find an answer to this young girl’s

Mrs Barrett said medication known to have worked on adults cannot be used on Emily because it is not suitable for children. One drug she has already tried left her ill in hospital for a week.

She said a young American girl had created a “hiccupop”, a lollipop, which she believes will stop hiccups as it worked for her but it had yet to be released for public sale.

She praised St Helier Hospital, Stanley Park High School and the Chiltern Health Centre who are all providing help to the youngster.

Other cases of people to have had chronic hiccuping include an American man, Charles Osborne,who is in the Guinness Book of World Records after having hiccups for 68 years from 1922 to 1990 – when they mysteriously stopped.

In 2007, teenager Jennifer Mee, from Florida, became famous for hiccuping about 50 times a minute for more than five weeks.

If you have an idea how to cure Emily’s hiccups, leave a comment in the box below.