Zsa Zsa Weerts

Chapter 2 42 not fulfill any of these Rome IV diagnoses. Possibly, a small subset might be defined as Rome IV unspecified functional bowel disorder. However, it is very likely that patients reporting abdominal pain or bloating/distension less than once weekly (without predominant constipation or diarrhea), will not fulfill any Rome IV diagnosis due to the new frequency threshold. Second, as the Rome criteria are not that universally used in routine clinical practice, in our opinion, patients with milder functional GI symptoms seeking health care, but not fulfilling one of the Rome IV diagnoses, should still be managed as functional GI disorders. With regard to future IBS research, patient inclusion should be based on the Rome IV criteria, in order to aim at agreement between studies. Nevertheless, this study demonstrates that the Rome IV IBS population is represented by younger females with higher overall gastrointestinal symptom severity, including comorbid psychological symptoms and lower quality of life compared to the Rome III IBS population. Therefore, results from Rome III IBS studies may not be directly comparable to those from Rome IV IBS populations, which has implications for future IBS research in particular.