Clinical Dimensions of Bloating in Functional Gastrointestinal Disorders.

Background/aims: Bloating is common bothersome symptoms and most studies conducted in the Western countries found that bloating was frequently associated with lower gastrointestinal (GI) symptoms but many patients complaint bloating as upper GI symptoms in the clinical setting. This study was conducted to assess the prevalence of bloating, and to identify symptom grouping and finally document the impact of bloating in the diagnosis of functional GI disorders.

Methods: Participants in a comprehensive health-screening cohort were enrolled. They were asked about demographic, medical, and social history and upper and lower GI symptoms by using a validated questionnaire. Factor analysis with principal component analysis method with varimax rotation was used.

Results: Among the total of 1050 subjects (mean age, 44.6 ± 10.2 years; females, 46.4%), significant bloating symptoms were found in 282 (26.9%); the prevalence of functional bloating was 6.9%. Factor analysis revealed a 5-component structure with upper GI symptoms, constipation, diarrhea-predominant irritable bowel syndrome (IBS), constipation-predominant IBS, and fecal incontinence. Abdominal bloating loaded on both the upper GI symptoms (0.51 of loadings) and constipation (0.40). On logistic regression analysis, bloating was more predictable for IBS (OR, 7.5; P < 0.001) than functional dyspepsia (FD; OR, 3.7; P = 0.002). Bloating was more frequently combined with IBS according to their severity, but this association was not detected in patients with FD.

Conclusions: Abdominal bloating is common symptom in about a quarter of patients and appears as upper as well as lower GI symptoms. However, abdominal bloating is more predictable for IBS, especially constipation-predominant IBS, than FD.