Introduction
Cognitive Behavioral Therapy (CBT) is an evidence-based treatment for Irritable Bowel Syndrome (IBS), demonstrating long-term improvements in symptoms and quality of life (QOL). However, its implementation is hindered by the complexity of treatment protocols, high time and financial costs, and limited accessibility in Japan.
Aims & Methods
This study aimed to develop a smartphone-based CBT application and evaluate its effectiveness in alleviating IBS symptoms.
Adults aged 18 or older who met the Rome IV criteria for IBS and scored ≥110 on the Japanese version of the IBS Symptom Severity Index (IBSSI-J) were enrolled. Twenty-six participants were randomly assigned to either the intervention group (n = 14) or the waiting-list control group (n = 12). Outcome measures included the IBSSI-J, Japanese versions of the IBS-QOL (IBS-QOL-J), Pain Catastrophizing Scale (PCS-J), and Visceral Sensitivity Index (VSI-J). A two-way ANOVA was conducted with group (intervention vs. control) and time (pre, mid, post, follow-up 1) as independent variables.
The intervention group used the app for 5–10 minutes daily over two months. The app included three components: psychoeducation, cognitive restructuring, and exposure. Psychoeducation consisted of educational materials and follow-up quizzes. Cognitive restructuring used gamified multiple-choice content (135 items), replacing conventional thought records. Exposure involved users creating individual anxiety hierarchies and recording their thoughts before and after exercises. The app visualized anxiety changes and progress via graphs.
Table 1.
Intervention module of the application
| Week | Module | Content |
| 1 | Psychoeducation
| Introduction to the vicious cycle of IBS symptom exacerbation. |
| 2 | Psychoeducation
Cognitive-Restructuring
| Understanding the link between cognition and symptoms; exploring alternative perspectives. |
| 3 | Psychoeducation
Cognitive-Restructuring
| Explanation of exposure therapy; preparing for symptom-related situations; continued cognitive restructuring.
|
| 4 | Cognitive-Restructuring
Anxiety Hierarchy
| Identifying anxiety-provoking situations and planning exposure tasks.
|
| 5-8 | Exposure
| Gradual exposure to selected situations based on the individual anxiety hierarchy.
|
| 9 | Psychoeducation
Summarization
| Post-intervention strategies and relapse prevention.
|
Results
Eleven participants in the intervention group and eight in the control group completed the program. Significant group × time interactions were observed for all outcome measures. For the IBSSI-J, the interaction was significant (F(3, 51) = 4.41, p < .001), with the intervention group showing greater improvement at mid-point (F(1, 17) = 5.54, p = .03, η² = .25). For the IBS-QOL-J, a significant interaction was found (F(3, 51) = 8.00, p < .001), with improvement evident at follow-up 1 (F(1, 17) = 6.65, p = .02, η² = .28). For the PCS-J, the interaction was significant (F(3, 51) = 3.83, p = .02), with improvements at post (F(1, 17) = 9.26, p = .01, η² = .35) and follow-up 1 (F(1, 17) = 5.83, p = .03, η² = .26). For the VSI-J, the interaction also reached significance (F(3, 51) = 3.32, p = .05).
Conclusion
The CBT-based app was effective in reducing IBS symptom severity. Its effects persisted after the intervention and extended to improvements in QOL, visceral anxiety, and pain catastrophizing—psychological factors associated with the maintenance and exacerbation of IBS. It is assumed that the cognitive restructuring component of the app facilitated cognitive diversification among participants. By empirically challenging the plausibility of these diversified cognitions through behavioral experiments in the form of exposure tasks, participants were able to further develop more adaptive thoughts. This process is considered to have contributed to the improvement of symptoms and enhancement of QOL. This digital approach may offer a viable solution to current barriers in CBT access.
