Researchers in New South Wales have made significant breakthroughs in the understanding of factors causing irritable bowel syndrome (IBS).

The scientists from the University of Newcastle (UON) and Hunter Medical Research Institute (HMRI) now believe IBS is a collection of individual diseases, rather than one illness.

The results of the study have been published in the New England Journal of Medicine, with researchers hoping it will re-frame understanding of the condition around the world.

Professor Nicholas Talley, pro vice-chancellor of global research at UON, said IBS is a condition affecting many Australians.

"IBS is very common, it affects at least one in 10 Australians and it's a chronic problem," he said.

"It's where people develop abdominal pain and they've also got a disturbed bowel habit.

"The problem with this disorder is (patients) often feel anxious or depressed with this disorder, and it also has all sorts of other symptoms that people experience.

"It's been a bit of a mystery, but the mystery is starting to become a little bit clearer lately."

IBS a collection of diseases

Professor Talley said researchers now believe IBS is an umbrella term for individual gut-related diseases.

He said those individual diseases include: people being genetically pre-disposed to gut issues, some patients developing the condition after a gut infection, and some people having a chronic gut infection which causes the symptoms.

"We're starting to recognise that IBS is not one disease, but many diseases," Professor Talley said.

"We've started to pick out some of the mechanisms, some of the causes for this set of problems.

"We found a particular gene that's linked to IBS and it appears to be important in some people with this disease. It's actually a mutation.

"We've also found that there's probably a chronic infection of the large bowel that's linked to this disease and we're doing more research to sort out how to best treat this and identify it. But it looks promising.

"We've also recognised that after you get something like gastroenteritis you can develop IBS too, and that group of people also seem to be a very discrete subset of the population.

"So there's a bunch of diseases here and by recognising what they are we may be able to even cure people in the near future."

Professor Talley said doctors need to start treating IBS on an individual case-by-case basis.

"It's not one treatment fits all, no doubt about that. We need to individualise treatment and I think we're getting closer to a personalised medicine approach," he said.

IBS linked to mental illness

The researchers have also found links between IBS and the development of mental illnesses.

"We've been able to show that there are some people who will develop their IBS and then develop serious anxiety for the first time," he said.

"We think that is related to changes in the gut, including inflammation that drives changes in the brain.

"We've been able to show too that if we block that inflammation in the brain we change things again, and we help.

"We're reasonably convinced that some anxiety disorders are driven by gut disease.

"If we can change the gut, if we can fix the gut, then we are very hopeful we'll be able to help some people with anxiety and other mental health [issues] and neurological disorders potentially."

Patients cautious of getting their hopes up

New South Wales man Joe Eisenberg has lived with irritable bowel syndrome for over 20 years.

"It has a variety of ways of paining and affecting me, therefore each one has a different way of me reacting to it," he said.

"I can get it from eating a little bit too much oil, or too milky or creamy, and then I'd have to run to the toilet within about five or 10 minutes."

While the prospect of a cure is a step closer, Mr Eisenberg is cautious of getting his hopes up.

"As long as it's not all hokey-pokey and meditation and needles and things like that. I've gone through that for the last 20-25 years," he said.

"I keep thinking 'well, if it's all to do with that, here we go again'.

"But if there's a cure I'll be the first one in the queue."