File: Hospitals in England have reported a sharp rise in the number of young people treated for inflammatory bowel conditions / Rex Features

Symptoms include recurring diarrhoea, pain after eating and extreme tiredness

Crohn’s disease is a long-term condition which causes the inflammation of a part of the digestive tract. The inflammation can occur anywhere from the mouth to the back passage but is most common in the gut.

The most widespread symptoms are recurring diarrhoea, pain after eating and extreme tiredness.

More and more people are being diagnosed with the disease, with some experts blaming a rise in the consumption of junk food and overuse of antibiotics could be to blame.

Hospitals in England have reported a sharp rise in the number of young people treated, from just under 5,000 16 to 29-year-olds in 2003 to more than 19,000 last year. Wales has also seen the number of cases increase more than double in that time.

But it’s still a relatively uncommon condition with estimates of the total number of sufferers in the UK ranging from 115,000 to 250,000.

Read more: Crohn’s disease hospital admissions surge 300%

The exact cause is unknown, but experts believe it could be genetic. It is believed the inflammation is caused by a disruption of the immune system – in which the body’s own defence system goes into overload, producing antibodies that do more harm than good.

Previous childhood infections may increase the likelihood of getting Crohn’s. Smokers are also twice as likely to develop the condition.

It has long been known that Crohn’s is a “disease of the rich”, with far more sufferers in Western nations than in developing countries.

This has led researchers to investigate what factors of the Western lifestyle may be driving the increase. Some say it could be junk food or overuse of antibiotics.

Another more speculative theory is that children growing up in the ultra-hygienic, germ-free environment of many Western homes may not have a fully-developed immune system because they have not been exposed to childhood infections.