Urgency as an Endpoint in Irritable Bowel Syndrome

Abstract

Background: The choice of endpoints is crucial for proper evaluationof agents in clinical trials of irritable bowel syndrome (IBS). Ina recently published draft guidance for IBS from the United StatesFood and Drug Administration (FDA), urgency was not consideredan appropriate primary endpoint. The FDA's position is that it is notclear how patients with diarrhea-predominant IBS (D-IBS) "defi neor describe urgency". The aims of this study were to evaluate theassociation of urgency with stool frequency and consistency in patientswith D-IBS and to describe results from patient interviews ontheir understanding of the term urgency.Methods: A retrospective analysis of clinical trial data in patientswith D-IBS was conducted. Analyses focused on the relationship ofurgency to stool frequency and consistency. Interviews were conductedwith patients with D-IBS to test their understanding of theterm urgency.Results: On the days that patients reported urgency, as comparedto the days that patients did not report urgency, they had more frequentbowel movements (3.9 versus 1.8) and looser stools (BristolStool Score: 5.4 versus 4.2). The differences for both parameters,evaluated on the days with or without urgency, were statisticallysignifi cant. In patient interviews, patients with D-IBS had a clearunderstanding of the concept and terminology of urgency and consideredit one of their two most bothersome symptoms.Conclusions: Urgency should be considered a suitable co-primaryendpoint in D-IBS studies.