Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic or recurrent abdominal pain or discomfort, usually in the lower abdomen, which is associated with disturbed bowel function and feelings of abdominal distention and bloating 1
that are often relieved by defecation. An estimated 10–15% of adults in North America suffer from IBS 2
, and it is associated with a significant reduction in health related quality of life 3
. IBS is one of the most common reasons for work and school absenteeism 4
. Estimates of annual direct and indirect costs associated with IBS exceed 41 billion dollars in major industrial countries 5
The pathophysiology of IBS includes alterations in intestinal motility, visceral hypersensitivity and abnormalities in the processing of visceral information. Until recently, most therapies for IBS have been directed at a specific intestinal symptom (e.g., diarrhea, constipation, or abdominal pain) and have not been effective for treating other symptoms associated with IBS. While more recent therapies have shown promise, treatment options for IBS remain limited. Therefore, it is not surprising that many patients with IBS have turned to complementary and alternative medicine (CAM) 6
such as acupuncture. In one survey, approximately one half of subjects with IBS reported using CAM 7
Acupuncture, an ancient traditional Chinese medical practice, is becoming more widely accepted and used in Western society 8
. Traditional Chinese medicine is based on a theory of energy or life force (“qi”) that runs through the body in channels called meridians. Qi is essential to health, and disruptions of this flow, which are believed to contribute to symptoms and diseases, can be corrected at identifiable anatomical locations (“acupoints”) with acupuncture. In IBS, acupuncture is believed to alter visceral sensation and motility by stimulating the somatic nervous system and the vagus nerve 9–11
A 2006 Cochrane Database article reviewed 6 randomized trials using acupuncture in IBS12
. The studies were generally of poor quality, included relatively small numbers of patients, and differed significantly in acupuncture method utilized. Limitations notwithstanding, this review found inconclusive evidence as to whether acupuncture is superior to sham acupuncture in IBS. Subsequently, Schneider et al. 13
published the results of a well conducted study in which 43 IBS patients were randomized to acupuncture or sham acupuncture. There was no significant difference between the response rates in patients receiving acupuncture and sham acupuncture on a specific quality of life measurement for functional bowel digestive disorders (FBDDQL) 14
although patients in both groups improved significantly compared to baseline.
Our study comparing acupuncture to sham acupuncture was nested within a larger study examining the impact of the patient-practitioner interaction in IBS patients. In this larger study, which served as the run-in period for our study, participants were randomized to three weeks of: 1) waitlist, 2) sham acupuncture (twice a week) with a ‘limited’ patient-practitioner encounter, or 3) sham acupuncture (twice a week) with an ‘augmented’ patient-practitioner encounter (i.e, a warm, friendly, and supportive patient-practitioner interaction). The results of this three-week run-in are reported elsewhere 15
. After three weeks, participants receiving sham acupuncture were seamlessly and unknowingly re-randomized to continue for another three weeks on either acupuncture or sham acupuncture with the same ‘limited’ or ‘augmented’ patient-practitioner encounter that they had received during the run-in phase of the trial. This second three week period comprises the acupuncture study reported here.
The aims of this trial were threefold: 1) to determine if acupuncture provides greater relief of IBS symptoms than sham acupuncture or waitlist control, 2), to determine if eliminating patients who responded to sham acupuncture during the run-in period (i.e., patients who responded to sham acupuncture during the 3 weeks prior to randomization to acupuncture or sham acupuncture) widens the response rate differences between acupuncture and sham acupuncture, perhaps to the point of statistical significance, and 3) to determine if an ‘augmented’ patient-practitioner interaction enhances the difference in response rates between acupuncture and sham acupuncture.