RATES of inflammatory bowel disease in Scotland are double previous estimates according to the most detailed study of Crohn's and colitis to date, using Edinburgh patient records.

Researchers from Edinburgh University said the increase can be traced back to the 1960s but it remains unclear exactly what is driving the upsurge.

They also warned that shortages of gastroenterologists in the NHS will become more acute as the number of people in Scotland living with these gut problems soars by around 12,000, to 55,000, over the coming decade.

The findings are based on an analysis of Lothian's adult inpatient admissions, pathology reports, a paediatric registry and prescribing data for the Lothian region, some of it dating back as far as 1990.

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It reveals that the current prevalence for inflammatory bowel disease (IBD) is one in 125 people, but the researchers predict that this will rise to one in 98 within 10 years.

They also stressed that they are "very confident" that results for Lothian - which are among the highest in the world - would be mimicked across the country.

Unlike many other diseases which increase in line with deprivation, the study showed no association between postcode and rates of IBD.

Diagnosis peaked in the 18 to 29 age group.

Dr Gareth-Rhys Jones said: "We are very confident that these numbers will be replicated throughout Scotland, throughout the UK, and even more generally, across the Western world.

"I think what this shows is that we have historically underestimated how common this condition is.

"The rates that we are reporting in Edinburgh are double what has previously been reported in the UK.

"This is only going to become more of an issue because every year the number of people with IBD is increasing by 4-5 per cent."

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Dr Jones said the annual increases now appeared to be fairly static, compared to pre-1990 studies which showed rising incidence.

However, prevalence will rise as the number of new cases each year outnumber deaths among older people living with the conditions.

He added that paediatric patient records for Edinburgh show that IBD is not a new phenomenon.

He said: "These are rates of IBD in children, but what we see is that it's just consistently gone up and up from that point.

"There's not a specific point in the last 60-70 years where we can say 'this is when it got bad'.

"For as long as we've been measuring it, it's just been getting worse."

IBD is an umbrella term for ulcerative colitis, which only affects the colon, and Crohn's disease, which can affect any part of the digestive system.

Symptoms vary over time but flare-ups include extreme fatigue, abdominal bloating and pain, weight loss, severe diarrhoea and bloody stools.

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It is unclear what causes it, but it is significantly more common in Western societies.

Incidence has also been climbing rapidly in countries such as India and China which are becoming increasingly Westernised.

Dr Jones said: "There seems to be something bad about a Western lifestyle that predisposes you to gut inflammation.

"We know that 20-30% of the disease is down to the genes you inherit, but the rest is environment.

"Diet is really important. Smoking is really important in Crohn's disease. A Western lifestyle and an industrialised lifestyle more generally.

"If you look at China, they are seeing an absolute explosion of these conditions in the past 10 to 15 years and you can't account for such a rapid rate of change from genetics.

"What we've done today is basically phase one - working out the scale of the problem.

"Phase two is really trying to unpick what the environmental triggers are - what is it in people's diets, or in their lifestyle in terms of stress and pollution, that sets it off?"

Sarah Sleet, CEO of Crohn’s & Colitis UK’s: “This important study contributes to the growing evidence that the prevalence of IBD is significantly higher than currently recognised.

"Crohn’s and Colitis are a hidden and growing health crisis and the number of people living with the conditions is huge.

"These shocking higher figures must influence decision making in the NHS, and push forward the case for increased resources, improvements to IBD services and ultimately better care for people with Crohn’s and Colitis.”