Skip to main content

Research Repository

Advanced Search

A randomised trial of ondansetron for the treatment of irritable bowel syndrome with diarrhoea

Garsed, Klara; Chernova, Julia; Hastings, Margaret; Lam, Ching; Marciani, Luca; Singh, Gulzar; Henry, Amanda P.; Hall, Ian P.; Whorwell, Peter; Spiller, Robin C.


Klara Garsed

Julia Chernova

Margaret Hastings

Ching Lam

Profile Image

Professor of Gastrointestinal Imaging

Amanda P. Henry

Ian P. Hall

Peter Whorwell

Robin C. Spiller


Background: Irritable bowel syndrome with diarrhoea (IBS-D) is particularly debilitating due to urgency and episodic incontinence. Some 5-hydroxytryptamine 3 (5-HT3) receptor antagonists (5-HT3RAs) have proven effective but have serious side effects. Ondansetron, also a 5-HT3RA, has been widely used as an antiemetic with an excellent safety record for over two decades. Our aim was to assess its effectiveness in IBS-D.

Methods: 120 patients meeting Rome III criteria for IBS-D entered a randomised, double-blind, placebo-controlled crossover study of 5 weeks of ondansetron 4 mg versus placebo with dose titration allowed, up to two tablets three times daily in the first 3 weeks. Patients completed daily diaries documenting stool consistency using the Bristol Stool Form score. Gut transit was measured in the last week of each treatment. The primary endpoint was average stool consistency in the last 2 weeks of treatment.

Results: Ondansetron significantly improved stool consistency (mean difference in stool form between ondansetron and placebo −0.9, 95% CI −1.1 to −0.6, p less than 0.001). Compared with placebo, patients on ondansetron experienced fewer days with urgency (p


Garsed, K., Chernova, J., Hastings, M., Lam, C., Marciani, L., Singh, G., …Spiller, R. C. (2014). A randomised trial of ondansetron for the treatment of irritable bowel syndrome with diarrhoea. Gut, 63(10), 1617-1625.

Journal Article Type Article
Acceptance Date Nov 17, 2013
Online Publication Date Dec 12, 2013
Publication Date 2014-10
Deposit Date May 8, 2014
Publicly Available Date May 8, 2014
Journal Gut
Print ISSN 0017-5749
Electronic ISSN 1468-3288
Publisher BMJ Publishing Group
Peer Reviewed Peer Reviewed
Volume 63
Issue 10
Pages 1617-1625
Public URL
Publisher URL
Copyright Statement Copyright information regarding this work can be found at the following address: