The patients with quiescent CD were enrolled into this study between September 2019 and July 2020. Quiescent CD was defined as a Crohn’s disease activity index (CDAI) ≤ 150 and a C-reactive protein (CRP) level of ≤ 0.3 mg/dL.6 (link),13 (link) The CDAI is a validated standard calculated using the scores for bowel habits, abdominal pain, general condition, Crohn’s disease-associated findings, use of medicines for diarrhea, abdominal mass sensation, hematocrit, and body weight.14 (link) Prior to this study, endoscopic mucosal healing had been confirmed by colonoscopy and/or capsule endoscopy. Since we did not have a validated Japanese version of the Rome IV diagnostic questionnaire, we used a Japanese version of the Rome III diagnostic questionnaire for functional gastrointestinal disorders to evaluate IBS-like symptoms.15 (link) The patients classified as diarrhea-predominant IBS (IBS-D) was included in this study. The patients who completely met the conclusion criteria of both quiescent CD and IBS-D were recruited consecutively. Clinical information and symptoms were evaluated using a self-completed symptom questionnaire.
This study was performed with approval (No. 3158) from the Ethics Committee of Hyogo College of Medicine and registered in the University Hospital Medical Information Network (Registration No. UMIN000041577). Patients who had given fully informed consent were enrolled, and the study was conducted according to the principles governing human research stipulated by the Declaration of Helsinki. All authors had access to the study data and reviewed and approved the final manuscript.