Time-Restricted Eating and Symptom Severity in Irritable Bowel Syndrome: Results from a Pilot Study

Background/Objectives: Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder affecting approximately 5-10% of the population, with many individuals reporting insufficient improvement from treatment options. This study aimed to investigate whether time-restricted eating (TRE) could alleviate symptoms in patients with IBS. Methods: This single-group intervention study included participants with IBS who followed an 8-week time-restricted eating protocol, defined as a daily 16-hour fasting period and an 8-hour eating window (16:8). Symptom changes were assessed using the validated IBS Symptom Severity Scale (IBS-SSS) at baseline and post-intervention. The study was not prospectively registered in an international clinical trial registry and was retrospectively registered in the Open Science Framework after completion of data collection. Results: A total of 134 patients were included in this study. After 8 weeks, 97 participants completed the study, showing a mean reduction in the IBS-SSS score of -100.2 (p<0.001). Subgroup analysis also demonstrated mean reductions in the IBS-SSS scores for participants with IBS-constipation (IBS-C) (-125.2, p<0.001), IBS-diarrhea (IBS-D) (-76.0, p<0.005), and IBS-mixed (IBS-M) (-93.1, p<0.001). Additionally, the participants experienced improvements in both self-reported physical and mental health. Conclusions: These preliminary findings suggest that TRE can be a supplementary tool for managing IBS symptoms, warranting controlled trials.