To investigate the spectra of functional gastrointestinal disorders (FGID) in outpatients in Japan, FGID were diagnosed and classified using ROME II. Patients who visited Social Insurance Shiga Hospital with symptoms lasting >12 weeks over a 12-month period without organic diseases were enrolled. A total of 61 patients answered the ROME II Integrative Questionnaire. The answers were analyzed automatically by a computer program according to the Codes for Rome II Integrative Questionnaire. Age-adjusted ratios of FGID patients were investigated. Of 61 patients, 54 were diagnosed as having FGID. The ratio of male/female was 29/25, and the age was distributed from 26 to 92 years (mean, 57.8 years). There was no significant difference in age between the sexes. The adjusted ratio of FGID patients increased with age with significant correlation (P=0.00385). Of the 54 patients, 23 (42.6%) had overlapping FGID. A total of 85 FGID were diagnosed in 54 patients (including 15 cases of unspecified functional bowel disorder, 14 of irritable bowel syndrome [IBS], 13 of functional fecal incontinence, 12 of functional abdominal bloating, and eight of functional dyspepsia [FD]). The adjusted ratio of patients was significantly correlated to age in cases of unspecified functional bowel disorder, functional fecal incontinence, and functional abdominal bloating, but not in IBS or FD. The ROME II Integrative Questionnaire and automatic analyzer were useful tools in diagnosing and classifying FGID. Approximately 40% FGID patients had overlapping conditions. The adjusted ratio of patients in some FGID was significantly correlated with age.