Bloating Is More Strongly Associated with Abdominal Pain Than with Stool Frequency in Irritable Bowel Syndrome with Constipation (IBS-C): 938

Purpose: Bloating is one of the most bothersome symptoms of IBS and is often difficult to treat. The pathogenesis of bloating is unknown. Bloating is common in IBS-C but the relationship between bloating and constipation is unclear. The aims of this study were to evaluate the relationship between bloating and stool frequency (SF) as a marker of constipation and to determine if bloating is more correlated with SF in IBS-C or with other IBS symptoms, particularly pain. Methods: Data from 2,472 women in three published multinational, double-blind, randomized, placebo-controlled Phase III trials in IBS-C were evaluated. Two studies utilized a 6-point severity scale for both bloating and abdominal pain/discomfort; the third used a 7-point scale. An adjustment was made to equalize the ratings between studies. SF was quantified in all studies by counting stool passage. Data from baseline and at the end of 1 month of treatment with tegaserod or placebo were used in this analysis. Pearson correlation coefficients for bloating severity, pain/discomfort severity and SF were obtained by study and treatment. Results: There was a strong positive correlation between severity scores for bloating and for abdominal discomfort/pain in all three studies. The correlation coefficients for this association ranged from 0.64 to 0.9 at baseline and from 0.7 to 0.9 at month 1 with similar results for both treatment groups. In contrast, there was only a weak negative correlation between bloating and SF (range −0.20 to −0.06). Conclusions: In women with IBS-C, bloating severity exhibits a strong positive correlation with abdominal pain/discomfort but not with SF. Therefore, medical therapy that targets only constipation to produce increased SF is not likely to also relieve bloating.