OBJECTIVE: Inflammatory Bowel Diseases (IBD) are a group of chronic immune-mediated digestive disorders that can cause significant psychological distress and disability. IBD-informed cognitive behavioral therapy (CBT) may reduce psychiatric co-morbidity and improve health related quality of life. We herein examine the psychotherapy process variables relevant to implementation of a manualized CBT for IBD protocol delivered by therapists with no prior knowledge of IBD. METHOD: In the ADEPT Trial (Addressing Disability Effectively with Psychosocial Telemedicine - NCT05635292), 30 patients with IBD received up to 8 sessions of manualized CBT for IBD delivered via telehealth by one of 5 licensed PhD level clinical psychologists skilled in CBT but naïve to IBD prior to the study. All treating psychologists received training in IBD-informed CBT. Videos of the CBT sessions were rated by trained raters for psychotherapy process variables including therapist competence, fidelity to the manual, therapeutic relationship, and the content of patient themes. We also evaluated the association between process variables and outcome, measured as reductions in the IBD-Disability Index. RESULTS: All general therapists were highly competent in delivering IBD-informed CBT after training and showed fidelity to the treatment manual. Fidelity to teaching deep diaphragmatic breathing was associated with greater reductions in disability. Patient themes were associated with baseline disability and outcome. CONCLUSIONS: IBD-informed CBT can be delivered successfully by CBT therapists with no prior knowledge of IBD as a flexible modular therapy manual applied to a medically complex patient population.