Epidemiological, Clinical, and Psychological Characteristics of Individuals with Self-reported Irritable Bowel Syndrome Based on the Rome IV vs Rome III Criteria

OBJECTIVES: Few studies have examined the effects of applying the Rome IV criteria for irritable bowel syndrome (IBS) vs the previous standard, the Rome III criteria. We conducted a cross-sectional survey of individuals who self-identify as having IBS to examine this issue. METHODS: We collected complete demographic, symptom, mood, and psychological health data from 1375 adults who self-identified as having IBS, but were not recruited from a referral population. We applied the Rome III and the Rome IV criteria simultaneously to examine what proportion met each of these diagnostic criteria for IBS. We measured the level of agreement between the Rome III and Rome IV criteria, and assessed for presence of an alternative functional bowel disorder in individuals who no longer met diagnostic criteria for IBS with the more restrictive Rome IV criteria. Finally, we compared characteristics of individuals who met only Rome III criteria with those who met Rome IV criteria. RESULTS: In total, 1080 of 1368 individuals (78.9%) with IBS met the Rome III criteria. In contrast, 811 of 1373 individuals (59.1%) with IBS met the Rome IV criteria. Agreement between the criteria was only moderate (Kappa = 0.50). Among those who no longer had IBS according to the Rome IV criteria, 33 (11.5%) met Rome IV criteria for functional constipation, 118 (41.3%) for functional diarrhea, 68 (23.8%) for functional abdominal bloating or distension, and 67 (23.4%) for an unspecified functional bowel disorder. Individuals with Rome IV-defined IBS had more severe symptoms, and a higher proportion had a mood disorder and evidence of poor psychological health, compared with individuals who only met the Rome III criteria for IBS (P < .001). CONCLUSIONS: The characteristics of people who believe they have IBS differ between those who meet criteria as defined by Rome IV vs Rome III, including the spectrum of disease severity. Studies are needed to determine how these changes will affect outcomes of clinical trials.