Background: Inflammatory bowel disease (IBD) patients with persistent symptoms despite no or minimal inflammation are frequently described as having an overlap of IBD and irritable bowel syndrome (IBD-IBS). Limited data are available on how IBS impacts the individual patient with IBD. In this study, we aimed to evaluate the prevalence of IBD-IBS and investigate its impact on patient-reported outcomes. Method: We performed a cross-sectional analysis within the CCFA Partners Study. Bivariate analyses and logistic regression models were used to investigate associations between IBD-IBS and various demographic, disease factors, and patient-reported outcomes including anxiety, depression, sleep disturbances, pain interference, and social satisfaction. Results: Of the 6309 participants included, a total of 1279 (20%) reported a coexisting IBS diagnosis. The prevalence of IBD-IBS in this cohort was similar within disease subtypes. A diagnosis of IBD-IBS was associated with higher narcotic use compared with those with no IBS diagnosis for both Crohn's disease, 17% versus 11% (P < 0.001) and ulcerative colitis/indeterminate colitis, 9% versus 5% (P < 0.001). Quality of life, as measured by Short Inflammatory Bowel Disease Questionnaire (SIBDQ) was lower in patients with IBD-IBS compared with those without. IBD-IBS diagnosis was associated with anxiety, depression, fatigue, sleep disturbances, pain interference, and decreased social satisfaction. Conclusions: In this sample of patients with IBD, high prevalence of concomitant IBS diagnosis was observed. IBD-IBS diagnosis was associated with increased narcotic use and adverse patient-reported outcome. Appropriate diagnosis, treatment, and counseling may help improve the functional status of IBD-IBS patients and decrease narcotic use.