Bloating is associated with worse quality of life, treatment satisfaction, and treatment responsiveness among patients with constipation-predominant irritable bowel syndrome and functional constipation

Background: The management of bloating is unclear and its relationship with patients' well-being and treatment satisfaction independent of other abdominal symptoms is uncharacterized. We evaluated the association of bloating with patient-reported outcomes. Methods: Thirty-nine centers for functional gastrointestinal disorders joined the laxative inadequate relief survey. We enrolled 2203 consecutive outpatients with functional constipation (FC) or constipation-predominant irritable bowel syndrome (IBS-C) in two cross-sectional waves. Both wave 1 and 2 included the SF-12, the patient assessment of constipation-symptoms (PAC-SYM), and the treatment satisfaction questionnaire for medication (TSQM-2). Wave 2 only included a global rating of change (GRC) scale to assess patients' assessment of efficacy concerning treatment switches occurred in the 3 months prior to the interview. Bloating in the abdomen was defined on the basis of PAC-SYM item 3. Key Results: The average age was 50.1 years (SD, 16.7) and 82.1% of patients were women. The prevalence of bloating was 91.6% (n = 1970). Bloating was associated with SF-12 Physical Composite Score (p < 0.01), SF-12 Mental Composite Score (p < 0.01), GRC (p < 0.01), Satisfaction with treatment effectiveness (p < 0.01), convenience of administration (p < 0.01), and side effects (p < 0.01) after adjustment for possible confounders. Conclusions & Inferences: Our data suggest that patients regard bloating as a key element in assessing clinical changes and treatments' efficacy as this symptom exerts a strong influence on patient-reported outcomes independent of possible confounders and other symptoms of constipation. Our data provide the rationale to investigate the efficacy and tolerability of new treatments specifically addressing this important, yet disregarded, patients' complain.