1. Systematic review of the comorbidity of irritable bowel syndrome with other disorders: What are the causes and implications? 
William E. Whitehead, Olafur Palsson, Kenneth R. Jones 
Gastroenterology 
Volume 122, Issue 4, Pages (April 2002)
DOI: /gast
Copyright © 2002 American Gastroenterological Association Terms and Conditions

2. Fig. 1
Annual outpatient visits by IBS patients and control subjects. (Data from Levy et al.1).
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions