A UK registry study comparing the new Rome V IBS diagnostic criteria with Rome III and Rome IV found that Rome V identifies a larger group of patients but generally a less severely affected population. Among 1,275 participants with complete data, 70% met Rome V criteria, compared with 59% under Rome IV and 78% under Rome III. Rome V expands the definition of IBS to include abdominal discomfort as well as pain and reduces the required symptom frequency from once a week to three days a month.
The patients captured by Rome V had lower symptom severity, fewer psychological symptoms, better quality of life and lower healthcare costs than those who met Rome IV but no longer qualified under Rome V. IBS-related healthcare costs were £415 versus £1,046 over the previous 12 months.