Hypnotherapy seems to be an effective long term treatment for irritable bowel syndrome, research finds.
Hypnotherapy had a long-term effect
IBS is a very common disorder affecting up to 15% of the population at any one time, but is difficult to treat.
Researchers from Withington Hospital, Manchester, found hypnotherapy helped 71% of patients - and its effect lasted up to five years after treatment.
The research, based on 200 patients, is published in the journal Gut.
The patients were given one hour sessions of hypnotherapy for up to 12 weeks.
Symptoms of irritable bowel syndrome
A feeling of incomplete emptying of the bowels
Nausea, belching and vomiting
A need to rush and open the bowels
They were asked to assess their symptoms, quality of life and levels of anxiety and depression before and after treatment - and for up to six years after completing the course.
The majority of patients found that hypnotherapy reduced the severity of their IBS symptoms, and continued to do so for years.
Even those who said the effect began to wear off with time, found that the deterioration was slight.
Hypnotherapy also seemed significantly to reduce levels of anxiety and depression - however, the effect here did begin to tail off slightly over time.
But patients also said they took fewer drugs and did not need to see their doctors as often after they had had a course of hypnotherapy.
The researchers say the sustained improvements in most of the patients cannot be attributed to other treatments as fewer than one in 10 patients attempted alternatives after completing their hypnotherapy sessions.
Previous research has shown hypnotherapy to have a beneficial effect on IBS in the short term - but not over a longer period.
Critics say hypnotherapy is an expensive treatment.
But the researchers argue that the cost would be more than offset by a reduction in demand for prescription drugs.
Lead researcher Dr Wendy Gonsalkorale told BBC News Online: "While other studies have shown that symptoms have improved by the end of the course of treatment, the real significance is our finding that these effects are sustained after treatment sessions have finished, rather than patients just reverting back to their original state.
"We firmly believe that hypnotherapy should be available as a standard treatment for all patients with IBS."
Dr Gonsalkorale said it was unclear what caused IBS, and why hypnotherapy should help.
However, she said the condition was possibly linked to problems with muscle movement, or to increased sensitivity of the gut lining.
She said hypnotherapy may help the patient to gain better control over the way their gut works by influencing the release of hormones, or the nerve links between the gut and the brain.
It may also alter the way that the brain responds to incoming pain messages.
"For some patients, psychological factors and stresses may play a role in triggering or at least exacerbating symptoms.
"Whether or not they are the primary cause is still very debatable. Hypnosis can be used as a form of relaxation, to reduce stress.
"But it is not the whole story by any means. We know also that the therapy alters the way patients think about their symptoms."
Dr Mark Cottrill, a trustee of the IBS Network and a GP in Wigan, told BBC News Online his practice had employed the services of a hypnotherapist to treat IBS patients for a short time.
"She proved extremely popular and within months she had a three to four month waiting list," he said.
"But we had to end the sessions because we had no funding for them. It can cost £600 per patient and the money has to be found upfront."