Lower and Upper Gastrointestinal Symptoms Differ Between Individuals With Irritable Bowel Syndrome With Constipation or Chronic Idiopathic Constipation

BACKGROUND/AIMS: We evaluated the distribution of lower and upper gastrointestinal (GI) symptoms among individuals with irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) in a nationwide survey. METHODS: Individuals (≥ 18 years of age) were identified from a nationwide sample of > 70 000 United States adults. Participants completed the National Institutes of Health GI Patient Reported Outcomes Measurement Information System (NIH GI-PROMIS) questionnaire. Symptom frequency and intensity in the prior 7 days were assessed using validated PROMIS scores. Odds ratios (OR) with 95% confidence intervals (CI) were calculated to compare symptom prevalence in IBS-C vs CIC, and one-way ANOVA was used to assess differences in PROMIS scores. Regression analysis was performed to adjust for demographic variables. RESULTS: Nine hundred and seventy adults met eligibility criteria (275 with IBS-C, 734 with CIC). Demographics were similar among groups except for education, marital and employment status, and income. Adjusting for demographic differences, GI-PROMIS scores of global GI symptoms were higher in IBS-C (251.1; 95% CI, 230.0–273.1) compared to CIC (177.8; 95% CI 167.2–188.4) (P < 0.001). Abdominal pain was more prevalent (OR, 4.3; 95% CI, 2.9–6.6) and more severe (P = 0.007) in IBS-C. Constipation was more severe in IBS-C (P = 0.011). Incontinence was more common (OR, 2.9; 95% CI, 1.3–6.3) but just as severe (P = 0.389) in IBS-C versus CIC. Regarding upper GI symptoms, the prevalence of dysphagia, heartburn, and nausea were similar. However, IBS-C individuals had more severe heartburn (P = 0.001). CONCLUSION: GI symptoms are generally more severe in IBS-C compared to CIC, however abdominal pain, bloating, and upper GI symptoms still commonly occur in CIC.

Estimating the Contribution of Acute Gastroenteritis to the Overall Prevalence of Irritable Bowel Syndrome

BACKGROUND/AIMS: Recent studies reveal that acute gastroenteritis can precipitate irritable bowel syndrome (IBS) symptoms leading to the concept of post-infectious IBS. However, the overall contribution of gastroenteritis to the total IBS prevalence is unknown. In this exercise we try to estimate the contribution of gastroenteritis in IBS using the published literature and a longitudinal approach. METHODS: Existing literature was reviewed to determine the incidence of IBS after gastroenteritis, the rate of remission over time, data on rates of gastroenteritis in a given population and any patterns of resistance to these effects in human populations. This produced 3 models. The first assumed all humans were susceptible to gastroenteritis and its ability to produce IBS. The second assumed (using meta-analysis data) that 90% of humans in a given outbreak would be resistant to this effect. The third model used a high gastroenteritis exposure rate as might be seen in military deployment. RESULTS: In model 1, the prevalence was unrealistically high with an eventual steady state of 43.6% of the population affected by IBS. In a very conservative approach (model 2), steady state was achieved after 10 years to an overall prevalence of 8.9%. Interestingly, based on a high 1 year exposure rate such as military deployment, the maximum prevalence (steady state) was reached before 1 year suggesting high risk. CONCLUSIONS: Although hypothetical in approach, based on conservative estimates in existing literature the contribution of gastroenteritis to the overall prevalence of IBS is substantial.