Background: Sexual difficulties are common in individuals with inflammatory bowel disease (IBD). Aims: This study aimed to document sexual difficulties in IBD; to investigate longitudinal patterns in these difficulties; and to identify biopsychosocial factors that may serve as predictors of these difficulties. Methods: A longitudinal study was conducted, with IBD outpatients completing three questionnaires across 2 years. Items assessed biopsychosocial variables (e.g., age, PHQ-9, Multidimensional Scale of Perceived Social Support) and sexual difficulties (Golombok-Rust Inventory of Sexual Satisfaction). Findings: Patients reported a moderate level of sexual difficulties, with 17.5–74.5% exceeding the threshold of clinical significance across domains. No significant changes in sexual difficulties occurred across the study period. Biopsychosocial factors accounted for up to 25.2% of the variance in sexual difficulties, with age, depressive symptoms, pain-related disability, perceived social support, and optimism associated with these difficulties in the hypothesised directions. Conclusions: Patients reported significant sexual difficulties in several domains, with a high degree of stability over time. Biopsychosocial factors were associated with reported sexual difficulties, particularly older age and lower perceived social support. These factors are suggested as targets for intervention research.