Background: The Inflammatory Bowel Disease Questionnaire (IBDQ) is the most widely used disease-specific health-related quality of life questionnaire for patients with inflammatory bowel disease. However, little has been reported about the validation of IBDQ for patients with ulcerative colitis after surgery. The aim of this study was to assess the validity and reliability of the Japanese version of IBDQ in patients with ulcerative colitis after total proctocolectomy and ileal pouch anal anastomosis (IPAA). Methods: The validity and reliability of the Japanese IBDQ were assessed in patients with ulcerative colitis who had received IPAA in our hospital. We mailed them the Japanese IBDQ and a supplemental questionnaire on bowel function, which was developed at our institution. Internal consistency, discriminative validity, and factor validity were assessed. Results: Of the 121 patients to whom we sent the questionnaires, 64 patients (53%) participated in this study. The Japanese IBDQ scores correlated well with Cronbach's alpha value (0.800 to 0.923) and daily life satisfaction score (Pearson's r, 0.492 to 0.700). The total IBDQ score and two subscale scores of the IBDQ, "bowel symptoms" and "systemic symptoms," correlated well with daily bowel-movement frequency (Pearson's r, -0.256 to -0.329). Factor analysis revealed a four-factor structure, and all correlations among factors were moderately positive (0.337 to 0.465). Although the factor distribution was not clearly divided into the four IBDQ subscales, these four factors showed a marked tendency to represent the IBDQ subscales independently. Conclusions: The Japanese IBDQ is a valid and reliable instrument for the assessment of Japanese patients with ulcerative colitis after IPAA.