Predictors of patient-assessed illness severity in irritable bowel syndrome

Am J Gastroenterol. 2008 Oct;103(10):2536-43. doi: 10.1111/j.1572-0241.2008.01997.x. Epub 2008 Jun 12.


Background: Conceptual models suggest that "irritable bowel syndrome (IBS) severity" is a multidimensional outcome that is related to, yet distinct from, health-related quality of life (HRQOL). Existing severity questionnaires are largely based on physician rather than patient-based ratings. Since severity is a patient-centered outcome, it is essential that future instruments are based on patients' self-perceptions of severity. We measured patient-derived predictors of severity in a large cohort of IBS patients.

Methods: We performed a cross-sectional analysis in 755 IBS patients recruited at a university-based center. Subjects completed a bowel symptom questionnaire, SCL-90, and SF-36. The main outcome was patient-assessed "overall severity of gastrointestinal symptoms," as measured on a 0-20 scale (20 = most severe). We first developed a conceptual model of IBS, and then performed bivariate analyses to identify biopsychosocial predictors of severity. We then entered significant predictors into a multivariable model to measure the independent association of each predictor with severity.

Results: Six factors predicted severity: (a) abdominal pain rating (P < 0.001); (b) belief that "something serious is wrong with body" (P < 0.001); (c) straining with defecation (P= 0.001); (d) myalgias (P= 0.02); (e) urgency with defecation (P= 0.03); and (f) bloating (P= 0.05). Severity correlated highly with HRQOL in bivariate, but not multivariate, analysis.

Conclusion: Patient-derived severity in IBS is related to, yet distinct from, generic HRQOL. IBS severity is predicted by abdominal pain, bloating, straining, urgency, myalgias, and disease-related concern. These symptoms fall along both poles of the "brain-gut axis," indicating that a full assessment of patient severity must include a balanced biopsychosocial history.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdominal Pain / diagnosis
  • Abdominal Pain / epidemiology
  • Abdominal Pain / etiology*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Incidence
  • Irritable Bowel Syndrome / complications*
  • Irritable Bowel Syndrome / diagnosis
  • Male
  • Middle Aged
  • Pain Measurement
  • Prognosis
  • Quality of Life*
  • Retrospective Studies
  • Severity of Illness Index*
  • Surveys and Questionnaires