People who experience high levels of stress and anxiety appear to be more likely to develop irritable bowel syndrome(IBS)following a severe gastric infection,UK and New Zealand researchers report.A variety of studies have suggested that the cause of IBD has phychological and behavioural components,experts said."This study shows that various psychological factors,particularly stress,anxiety and a tendency to push oneself to keep going when ill and then collapse in response,interact with the physical illness is causing IBS,'' an expert said.In their study,the researchers looked at 620 patients who tested positive for stomach inflammation from a bout of infection with a bug called Campylobacter.None of the participants had previously suffered from IBS or serious bowel conditions.