Overview of Irritable Bowel Syndrome Arnold Wald, MD Professor of Medicine Department of Gastroenterology, Hepatology, and Nutrition University of Pittsburgh Medical Center Pittsburgh, Pennsylvania

Irritable Bowel Syndrome Chronic or recurrent GI symptoms Lower abdominal pain/discomfort Altered bowel habits Bloating Not explained by structural or biochemical abnormalities

IBS Clinical Subgroups Constipation predominant Diarrhea predominant Alternating constipation/diarrhea

IBS Clinical Subgroups Constipation predominant Diarrhea predominant Alternating constipation/diarrhea

Rome II Criteria for IBS At least 12 weeks or more, which need not be consecutive, in the preceding 12 months, of abdominal discomfort or pain that has 2 out of 3 features: Relieved by defecation Onset associated with a change in frequency of stool Onset associated with a change in form (appearance) of stool Gut. 1999.

Epidemiology of IBS in US (15% to 20% of Population) CONFIDENTIAL Epidemiology of IBS in US (15% to 20% of Population) Specialists 5% Primary care 15% Nonconsulters 80% 25% to 50% of referrals to GIs are IBS

Prevalence of Disorders in US IBS: 15% - 20% Dyspepsia: 8% GE reflux: 7% Asthma: 4% Diabetes: 3%

IBS Symptoms Reduce Patient Well Being Abdominal pain Reduced sense of well being Altered bowel habits Cramps Bloating Constipation Diarrhea Urgency

Medical Costs Associated With IBS Estimated $8 billion annually in direct costs Increased physician visits for both GI and non-GI complaints IBS patients incur 74% more health care costs than do non-IBS sufferers Drossman, et al. Dig Dis Sci. 1993;38(9):1569-1580. Talley, et al. Gastroenterology. 1995;109(6):1736-1741.

Impact of IBS on Work Missed work: 30% (1.7 days) Reduced days: 46% (3 days) Turned down promotion: 16% Changed job, health reasons: 9% Changed work schedule: 8% Hahn BA, et al. Digestion. 1999;60(1):77-81.

Pathophysiology of IBS: A Biopsychosocial Disorder Biological Altered GI motor activity Altered visceral sensation Psychosocial Behavioral Cognitive Emotional

Multiple Medications Are Used to Treat IBS Anticholinergics Tricyclic antidepressants SSRIs Antidiarrheals Bulking agents Laxatives Alosetron* *Data support efficacy for diarrhea-predominant IBS.

New Treatment Paradigm for C-IBS IO 13 New Treatment Paradigm for C-IBS 5-HT4 agonists Altered motility Altered sensation