Acupuncture Treatment for Irritable Bowel Syndrome: A Double-Blind Controlled Study

Irritable bowel syndrome (IBS) is a functional condition that affects approximately 15% of the population, especially adults between 30 and 50 years of age, characterized by abdominal pain, altered bowel habits, and discomfort without an identifiable organic cause. Despite its high prevalence, therapeutic options remain limited and only modestly effective, motivating the search for alternative treatments such as acupuncture. This pioneering study, conducted in Israel between January and June 1999, represents the first double-blind controlled investigation of acupuncture in the treatment of IBS. Researchers recruited patients through gastroenterologists in the region, including those who met the 1990 Rome criteria and had presented symptoms for at least one year.

After rigorous assessment to exclude organic disease, 25 patients completed the study protocol. The methodology used a crossover design in which each participant received both true and sham acupuncture at different time points, serving as their own control. True acupuncture was applied at LI-4 (Large Intestine meridian), located between the first and second digits in the metacarpal region, while sham acupuncture used point BL-60 (Bladder meridian) in the paravertebral region at the level of T-6. Each treatment consisted of two 30-minute sessions over 4 weeks, with a 3-week washout period between the different types of acupuncture to eliminate residual effects.

Outcomes were assessed through weekly questionnaires using a 1-to-5 visual analog scale, in which patients rated changes in eight different symptoms. The findings revealed some statistically significant but limited improvements. After the first session of true acupuncture, there was a significant improvement in overall well-being (p = 0.05) and reduction of abdominal pain (p = 0.04 in the second session). Patients with alternating diarrhea and constipation also showed significant improvement (p = 0.027) after the first true session.

However, these effects were not consistently maintained over the course of treatment. Acupuncture did not demonstrate significant benefits for abdominal distension, discomfort relieved by defecation, or presence of mucus in stool. The mechanism proposed by the authors is based on the visceral hyperalgesia theory, suggesting that acupuncture could influence the visceral sensory system through stimulation of the somatic sensory system. The release of endogenous opioid peptides, such as endorphins and enkephalins, was also considered as a possible explanation for the analgesic effects observed.

Although results from true acupuncture were consistently superior to sham, the global statistical analysis did not demonstrate significant differences between groups. The clinical implications of this study are limited because of the small sample size and inconsistent results. The authors acknowledge that despite the punctual positive effects observed, it was not possible to establish a clear therapeutic benefit of acupuncture for IBS. This conclusion led them to question the rationale for investments in larger studies on this therapeutic approach.

The study has important limitations, including the small sample size, high dropout rate (22%), and lack of long-term follow-up. Furthermore, the use of different acupuncture points for true and sham treatment may have influenced the results, since both points could have distinct physiological effects.