• pharmacoepidemiology;
  • nested case-control study;
  • oral steroids;
  • irritable bowel syndrome



To study whether irritable bowel syndrome (IBS) is associated with the use of oral steroids and whether there is a dose- or duration-response.


We followed up a cohort of 65 270 patients aged 20–74 years old enrolled in the General Practice Research Database in the UK with at least one prescription for steroids between 1994 and 1999. We performed a nested case-control analysis to estimate the adjusted relative risk (RR) associated with the use of steroids using unconditional logistic regression. Cases were 466 patients with a first episode of IBS during follow-up and controls were 5000 individuals randomly selected from the study cohort.


Current users of oral steroids presented an RR of 0.6 (95%CI: 0.4–0.9) compared to non-users. Doses greater than 10 mg of prednisolone daily were associated with an RR of 0.4 (95%CI: 0.2–0.9). When we stratified by age, no reduced risk of IBS was apparent under the age of 40 years. The reduced risk of IBS was greater among females than males.


Our results suggest that oral steroids can reduce the risk of a diagnosis of IBS. The apparent effect modification of age and sex deserves further research. Copyright © 2003 John Wiley & Sons, Ltd.