The Functional–Organic Dichotomy: Postinfectious Irritable Bowel Syndrome and Inflammatory Bowel Disease–Irritable Bowel Syndrome  Madhusudan Grover, Hans Herfarth, Douglas A. Drossman  Clinical Gastroenterology and Hepatology  Volume 7, Issue 1, Pages 48-53 (January 2009) DOI: 10.1016/j.cgh.2008.08.032 Copyright © 2009 AGA Institute Terms and Conditions

Figure 1 Unifying model for PI-IBS and IBD-IBS. There may be a common genetic predisposition that contributes both to susceptibility to responses to life stress via alteration of HPA function or infection, presumably through altered microbiota. These factors can produce immune dysfunction and inflammation via serotonergic and/or mucosal cytokine activation. These factors then produce the symptoms of pain and diarrhea consistent with these conditions, given that there is a permissive (ie, activated) psychosocial environment of life stress or abuse, psychologic distress and/or poor coping, or impaired psychologic adaptation to illness. cns, central nervous system; ec, enterochromaffin; 5-ht, serotonin. Clinical Gastroenterology and Hepatology 2009 7, 48-53DOI: (10.1016/j.cgh.2008.08.032) Copyright © 2009 AGA Institute Terms and Conditions