1. Volume 121, Issue 4, Pages 799-804 (October 2001)
Irritable bowel syndrome in twins: Heredity and social learning both contribute to etiology 
Rona L. Levy, Kenneth R. Jones, William E. Whitehead, Shara I. Feld, Nicholas J. Talley, Linda A. Corey 
Gastroenterology 
Volume 121, Issue 4, Pages (October 2001)
DOI: /gast
Copyright © 2001 American Gastroenterological Association Terms and Conditions

2. Fig. 1
Evidence for parental influence in IBS: prevalence of IBS in subgroups.
Gastroenterology  , DOI: ( /gast )
Copyright © 2001 American Gastroenterological Association Terms and Conditions