Functional gastrointestinal disorders (FGIDs) represent a common and important class of disorders within gastroenterology. Rome I, the first edition was published in 1994, with symptom-based diagnostic criteria for FGIDs. These criteria began to change the diagnostic approach to FGIDs, and no longer considered "diagnoses of exclusion" but rather "diagnoses of inclusion". Rome n, the second edition published in 2000, resulted from the continual process of analyzing new scientific and clinical evidence in the study of FGIDs. Rome n, diagnostic criteria for irritable bowel syndrome (IBS), was extended with a focus on the frequency of symptoms occurring twelve weeks (not necessarily consecutive weeks) within twelve months. ROME m, the third edition, conservative one, was published in September 2006, with changes made only where there is good evidence to do so. Some of the differences between Rome n and Rome m criteria are highlighted in this issue.