Mesalamine shows modest benefit in IBS

Treatment with mesalamine may only have modest efficacy for the global symptoms of irritable bowel syndrome (IBS), specifically IBS that causes increased diarrhoea, according to the results of a meta-analysis. However, the quality of evidence appears to be low.

Researchers searched multiple online databases for randomized controlled trials of mesalamine in IBS. Efficacy and safety were evaluated using dichotomous assessments of effect on global IBS symptoms, abdominal pain, bowel habit or stool frequency, and occurrence of any adverse event.

The initial search yielded 669 citations, of which eight met the eligibility criteria and were included in the meta-analysis. The total number of participants was 820, among whom 432 received mesalamine. Only one trial had a low risk of bias across all domains. The presence or absence of publication bias could not be determined due to too few studies.

Obtained using a random effects model, pooled data showed that compared with placebo, mesalamine was more efficacious for global IBS symptoms (relative risk [RR], 0.86, 95 percent confidence interval [CI], 0.79–0.95; number needed to treat [NNT], 10, 95 percent CI, 6–27) but not for abdominal pain or bowel habit or stool frequency.

In subgroup analyses, mesalamine was efficacious for global IBS symptoms in patients with IBS with diarrhoea (RR, 0.88, 95 percent CI, 0.79–0.99) but not in those with other predominant bowel habits or those with postinfection IBS.

The frequency of adverse events, which was reported in five trials only, was not significantly higher with mesalamine vs placebo (RR, 1.20, 95 percent CI, 0.89–1.63).

More adequately powered high quality studies on mesalamine in IBS are needed.