Spectra of functional gastrointestinal disorders diagnosed by Rome III integrative questionnaire in a Japanese outpatient office and the impact of overlapping

Background and Aims: The aim of this study was to establish the spectra of functional gastrointestinal disorders (FGID) in a Japanese outpatient office in Rome III. Methods: The Rome III Diagnostic Questionnaire for Adult Functional GI Disorders was translated into Japanese and an automated analyzing program was made according to the scoring algorithm of the questionnaire. Among 1378 patients who visited the outpatient office of the Social Insurance Shiga Hospital between May 2007 and April 2009, 112 serial patients who had symptoms possibly originating from the gastrointestinal (GI) tract, but did not have evidence of organic disease, were recruited. The subjects answered the questionnaire, and the answers were analyzed with the automatic analyzer. Results: During the study period, 94 of the 112 patients were diagnosed as having active FGID. Non‐overlapping FGID was diagnosed in 41 (43.6%) of those. Of the 41 non‐overlapping FGID patients, the most frequent diagnosis was irritable bowel syndrome (IBS) in 13 patients. Including overlapping cases, 165 FGID were diagnosed in 94 patients. The most frequent diagnosis was IBS in 33 patients (35.1%), the second was functional dyspepsia (FD) in 29 (30.9%) and the third was functional constipation in 21 (22.3%). The most frequent FGID overlapping with IBS was FD (36.4%), and the most frequent FGID overlapping with FD was IBS (41.4%). Of the 29 FD patients, 20 (69.0%) had functional bowel disorders. Conclusion: The most frequent FGID was IBS in both overlapping and non‐overlapping FGID patients. IBS and FD were the most frequent combinations in overlapping FGID. Most cases of FD are possibly parts of functional bowel disorders.