Home Page
Health Care Providers Section

E-mail this page   Printable View

Irritable Bowel Syndrome: Overview and Risk Factors

Irritable bowel syndrome (IBS) is characterized by chronic abdominal pain and altered bowel habits without an identifiable organic cause. It affects 10% to 15% of the U.S. population and represents up to 50% of all referrals to gastroenterologists.

The pathophysiology is unclear. To date, no physiologic or psychological etiology has been identified. Investigation has centered on abnormal gastrointestinal motility, hypersensitivity of gastrointestinal nerves, microscopic inflammation, infection, carbohydrate or bile acid malabsorption, and emotional stress, but clinical studies thus far are inconclusive.

Abdominal pain is the predominant symptom. Altered bowel habits are also often present and may occur as diarrhea, constipation, or alternating diarrhea and constipation. Other symptoms include bloating, incomplete evacuation, nausea, dyspepsia, dysphagia, reflux, and heartburn. The condition may also be accompanied by dysmenorrhea, urinary frequency and urgency, sexual dysfunction, or fibromyalgia.

Risk Factors

About half of cases present in patients less than 35 years of age. Women are affected twice as often as men.


Irritable Bowel Syndrome: Diagnosis >>