Usability study to guide the development of a cognitive behavioral therapy mobile application for reducing irritable bowel syndrome symptoms

Irritable bowel syndrome (IBS) is a prevalent disorder of gut-brain interaction in which psychosocial factors can exacerbate symptoms. Although cognitive behavioral therapy (CBT) has proven effective in alleviating IBS symptoms, its widespread implementation is limited by therapist shortages and the substantial time demands placed on both patients and clinicians. Mobile health–delivered Just-in-Time Adaptive Interventions (JITAIs) may overcome these barriers by providing continuous, personalized support. In this study, we simulated the core functions of a JITAI-based CBT application via Google Forms and gathered feedback from patients and clinicians for application development. In this three-month, multicenter observational study, ten adults meeting Rome IV criteria for IBS were enrolled from three psychosomatic clinics in Japan. Using Google Forms as a prototype, we delivered: a daily symptom diary, an exposure-therapy module with anxiety-hierarchy support and automated progression prompts, and an educational website. Usage data were recorded automatically, and feasibility, burden and satisfaction were assessed through post-study questionnaires with patients (n = 8) and semi-structured interviews with patients (n = 3) and physicians (n = 4). All ten participants (three women; mean age 28.4 years, range 18–52) completed the study (IBS with diarrhea [IBS-D] n = 6; IBS with constipation and diarrhea [IBS-M] n = 3; IBS unclassified [IBS-U] n = 1). Mean daily symptom diary completion rate was 94.9% (range 79.4–100%). A mean of 17.2 exposure sessions was recorded (range 2–53). In the usability questionnaire (n = 8/10), 6/8 (75%) agreed/strongly agreed that they wanted to continue the daily symptom diary, and 5/8 (62.5%) agreed/strongly agreed that they would recommend the prototype to others with IBS symptoms. The educational website was infrequently accessed. In patient interviews (n = 3), two participants who repeatedly practiced exposure reported perceiving declines in their Subjective Units of Distress over time, which encouraged continued practice. Interviews with physicians highlighted the need for an integrated mobile-application interface offering real-time visual feedback and streamlined hierarchy creation. High completion rates showed that smartphone self-tracking and exposure exercises were acceptable to patients with IBS. The future application should automate hierarchy building, embed educational content, and include participants with a broader range of IBS subtypes. Developing a dedicated JITAI application and conducting larger, controlled trials are needed to confirm clinical efficacy and long-term adherence.