Little is known about acupuncture's efficacy for Irritable Bowel Syndrome (IBS). This trial uses a manualized acupuncture treatment format that closely follows clinical practice and allows flexibility in designing individualized treatments. In addition, a second parallel qualitative study will follow a subgroup of patients throughout the trial to explore the relationships between patients' interpretations and understandings (what anthropologists call "meaning") of irritable bowel and their response to treatment. Cortisol levels (an important stress hormone) will also be assessed.

This will be a 3-arm trial: Active acupuncture, placebo acupuncture, and wait list.

Inclusion criteria:

Diagnosis of Irritable Bowel Syndrome based on Rome II criteria, including at least 12 weeks of abdominal discomfort or pain in the last 12 months with at least 2 of the following features:

• Relief with defecation
• Onset associated with a change in stool frequency
• Onset associated with a change in form/appearance of stool

Exclusion criteria:

• History of severe or intractable IBS, defined as continuous, unremitting and several abdominal pain greater than 12 hours/day
• Previous acupuncture treatment
• Concurrent diagnosis of any bowel disturbance that would interfere with the assessment or safety of the study
• History of laxative abuse
• Previous abdominal surgery (uncomplicated appendectomy, hysterectomy or cholecystectomy at least 6 months prior to entry acceptable)
• History of metabolic or inflammatory disease that may affect bowel motility, eg.g., inflammatory bowel disease, diabetes mellitus, sarcoidosis
• Other significant illness as determined by Investigator
• History of drug or alcohol abuse w/in 2 years;
• Insufficient knowledge of English to complete self-assessments to participate in study