SCIENTISTS have shown that a controversial theory concerning types of food helps patients with bowel problems.

It means thousands of people who suffer the effects of irritable bowel syndrome (IBS) may be helped if they cut out certain foods.

In what Yorktest Laboratories, of York, is calling a breakthrough, an independent scientific trial has shown that patients with IBS who followed a diet recommended by Yorktest found that their symptoms were relieved.

In the same York University trial, carried out at a hospital in Manchester, patients with IBS who followed a dummy diet reported no significant improvement in symptom control.

John Graham, managing director of Yorktest Laboratories, which has expanded around the world and now tests about 50,000 people a year, said: "We are so pleased and proud to be able to offer such a simple but effective solution to many thousands of sufferers of irritable bowel syndrome, which does not involve expensive and often ineffective medication."

The test requires patients to send a pin-prick sample of their blood to the York laboratory.

After analysis, in which the sample is exposed to a variety of food substances, each patient is given advice about which foods they should avoid.

The theory behind food elimination is based on the idea that it is possible to work out which foods patients should avoid by noting the appearance of antibodies in the blood sample.

"At long last, this is a solution which means that many patients can help themselves by simple dietary change," said Mr Graham.

News of the clinical trial were released to coincide with an event to mark Digestive Disease Week in the US.

Professor Trevor Sheldon, of the Department of Health Sciences at York University, said the test results "prove that food elimination can improve symptoms of irritable bowel syndrome".

Dr PJ Whorwell, consultant gastroenterologist at the University Hospital of South Manchester, said the trial provided evidence "that this approach may be very valuable in treating this condition".

Rachel Antoney, 40, from Tiverton, Devon, suffered from abdominal pains until she followed a Yorktest diagnosis and avoided oats and cow's milk. She said: "It has made a huge difference. It was well worth doing the test."

* The Yorktest helpline is 0800 074 6185.