Prevalence of fructose and lactose intolerances in Rome III-defined Irritable Bowel Syndrome (IBS) (n = 212), Functional Dyspepsia (FD) (n = 606), Functional Bloating (FB) (n = 109) and their subgroups, IBS-c: IBS with constipation (n = 37), IBS-d: IBS with diarrhoea (n = 67), IBS-m: IBS with alternating constipation and diarrhoea (n = 94), IBS-u: unclassified IBS (n = 14), FD-ppd: Functional Dyspepsia with postprandial distress (n = 368), FD-eps: Functional Dyspepsia with epigastric pain syndrome (n = 238) and FB: Functional Bloating (n = 109).