Measuring symptoms in the irritable bowel syndrome: development of a framework for clinical trials B. M. R. Spiegel* , ,à,§ , R. Bolus  ,à,§ , N. Agarwal § , G. Sayuk – , L. A. Harris**, S. Lucak    , E. Esrailian  ,§ , W. D. Chey àà , A. Lembo §§ , H. Karsan –– , K. Tillisch  ,à , J. Talley* ,§ & L. Chang  ,à,– *Department of Gastroenterology, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.   David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. à UCLA Center for Neurobiology of Stress, Los Angeles, CA, USA. § UCLA / VA Center for Outcomes Research and Education (CORE), Los Angeles, CA, USA. – Department of Gastroenterology, Washington University, St. Louis, MO, USA. **Division of Gastronenterology & Hepatology, Mayo Clinic, Scottsdale, AZ, USA.    Department of Gastroenterology, Columbia University, New York, NY, USA. àà University of Michigan Health System, Ann Arbor, MI, USA. §§ Division of Gastroenterology, Harvard Beth Israel Deaconess Medical Center, Boston, MA, USA. –– Atlanta Gastroenterology Associates, Atlanta, GA, USA. Correspondence to: Dr B. M. R. Spiegel, 11301 Wilshire Blvd, Bldg 115, Room 215, Los Angeles, CA 90073, USA. E-mail: bspiegel@mednet.ucla.edu Publication data Submitted 18 July 2010 First decision 5 August 2010 Resubmitted 23 August 2010 Accepted 31 August 2010 EV Pub Online 28 September 2010 SUMMARY Background There is uncertainty about how to measure patient-reported outcomes (PROs) in IBS. The Food and Drug Administration (FDA) emphasizes that PROs must be couched in a conceptual framework, yet existing IBS PROs were not based on such a framework. Aim To perform qualitative analyses to inform a new conceptual framework for IBS symptoms. Methods Following FDA guidance, we searched the literature for extant IBS ques- tionnaires. We then performed interviews in IBS patients to learn about the illness experience in their own words. We cultivated vocabulary to inform a conceptual framework depicted with domains, sub-domains, and item cate- gories, per FDA guidance. Results We identified 13 questionnaires with items encompassing 18 symptoms. We recruited 123 IBS patients for cognitive interviews. Major themes included: pain and discomfort are different – asking about discomfort is nonspecific and should be avoided in future PROs; bowel urgency is multi- faceted – PROs should measure bowel immediacy, controllability, and pre- dictability; and PROs should divide bloating into how it feels vs. how it looks. Symptom experience may be determined by 35-item categories within five domains: (i) pain; (ii) gas / bloat; (iii) diarrhoea; (iv) constipation; and (v) extraintestinal symptoms. Conclusions We applied FDA guidance to develop a framework that can serve as the foundation for developing a PRO for IBS clinical trials. Aliment Pharmacol Ther 2010; 32: 1275–1291 ª 2010 Blackwell Publishing Ltd 1275 doi:10.1111/j.1365-2036.2010.04464.x Alimentary Pharmacology and Therapeutics