BACKGROUND AND AIMS: Stress is a central factor in the pathophysiology of Irritable Bowel Syndrome (IBS), yet little is known about how stress and symptoms fluctuate together in daily life. This study characterized real-world associations between momentary stress and symptom severity in IBS, including whether stress predicts later symptoms and vice versa. METHODS: This was a prospective observational study conducted during the baseline phase of a randomized clinical trial among adults meeting Rome IV criteria for IBS (N = 357). Participants completed self-report measures of chronic stress and IBS symptom severity, followed by a 7-day ecological momentary assessment (EMA) with three surveys per day assessing momentary stress and symptom severity. RESULTS: Individuals with higher average stress during the EMA week experienced greater IBS symptom severity, and times of elevated stress relative to their usual level were linked to worse symptom severity, independent of chronic stress and symptom severity (both p < .001). A prospective stress-symptom association emerged during the afternoon-to-evening period, afternoon stress was associated with greater evening symptom severity (p = .002) and afternoon symptom severity was associated with greater evening stress (p = .04), whereas associations during the evening-to-next-morning transition were disrupted or inverse. CONCLUSION: Stress and symptoms are closely linked within the same moment, but also prospectively, particularly later in the day among adults with IBS. These findings highlight the dynamic nature of daily stress-symptom relationships and underscore the potential value of within-day stress management interventions for improving symptom control in IBS.
Yunusova et al. (Fri,) studied this question.