S560 The Strong Association Between Bloating, Abdominal Pain, and Global Irritable Bowel Syndrome (IBS) Symptom Scores in IBS With Diarrhea (IBS-D): A Phase 3 Trial Pooled Correlation Analysis of Individual Symptoms (2022)

Introduction: Although recurrent abdominal pain and altered stool consistency/frequency are diagnostic criteria for IBS, other symptoms (eg, bloating) are common and bothersome. Given the need to address multiple symptoms concurrently, the aim was to assess potential relationships between improvement in abdominal pain, bloating, and global IBS symptoms in patients with IBS-D. Methods: Data were analyzed post hoc from 2 identically designed, phase 3, randomized trials. Adults with IBS-D with both mean daily abdominal pain/discomfort and bloating scores, rated separately, of 2 to 4.5 on a 7-point Likert Scale (range, 0 [“not at all”] to 6 [“a very great deal”]) and a daily mean stool consistency score of ≥ 3.5 (range, 1 “very hard” to 5 “watery”) received rifaximin 550 mg TID or placebo for 2 weeks, with 10 weeks of treatment-free follow-up. In addition to symptoms above, fecal urgency was assessed daily, based on patients’ yes/no responses to “Have you felt or experienced a sense of urgency today?” Global IBS symptoms were also assessed daily (“In regards to all your symptoms of IBS; on scale of 0-6, how bothersome were your symptoms of IBS today?”). Pearson correlation analyses compared change from baseline in abdominal pain/discomfort, bloating, stool consistency, or fecal urgency and global IBS symptoms (overall [12 weeks] or by week). A coefficient (r) value of > 0.70-1.00 was considered a strong positive correlation ( > 0.50-0.70 [moderate] and ≤ 0.50 [weak-to-negligible]). Results: A strong positive correlation was observed between changes from baseline in both weekly average and daily symptom scores over time for bloating and abdominal pain/discomfort scores, bloating and global IBS symptom scores, and abdominal pain/discomfort and global IBS symptom scores (r ≥ 0.78; Table). The correlation between global IBS symptoms scores was moderate with stool consistency score assessed either weekly or daily and percentage of days with stool urgency assessed weekly (r ≤ 0.60; Table). When assessed by week, correlations for average weekly symptoms were consistent for Weeks 2 through 12 (Figure). Conclusion: Abdominal bloating and pain/discomfort are key symptoms in patients with IBS-D. These symptoms strongly correlate with each other and with global IBS symptom scores. Bloating and pain/discomfort may have a greater effect on patient perception of global IBS symptoms than altered stool consistency/fecal urgency. Therefore, effective therapies for IBS-D should target bloating as well as pain and diarrhea.Figure 1.: Correlation Coefficients for Weekly Average Symptom Score Comparisons, By Week IBS = irritable bowel syndrome. Table 1. - Overall Correlations Between Change From Baseline in IBS Symptom Scores Symptom Comparison Pearson Correlation Coefficient, r Average Symptom Scores Assessed Weekly Symptom Scores Assessed Daily Bloating and abdominal pain/discomfort scores 0.84 0.78 Bloating and global IBS symptom scores 0.84 0.79 Abdominal pain and global IBS symptom scores 0.92 0.88 Stool consistency and global IBS symptom scores 0.56 0.53 Percentage of days with fecal urgency and global IBS symptom scores 0.60 —* *Due to definition, not assessed daily.IBS = irritable bowel syndrome.