Comparison between the Effects of Acupuncture Relative to Other Controls on Irritable Bowel Syndrome: A Meta-Analysis

BACKGROUND: Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder with recurrent abdominal pain and altered defecation habits. We here attempted to determine the effect of acupuncture on IBS. METHODS: Randomized controlled trials (RCTs) published in CNKI, VIP, Wanfang, PubMed, Cochrane Library, EMBASE, Web of science, and ClinicalTrials.gov till July 17, 2019 were searched. Outcomes were total efficacy rates, overall IBS symptom scores, or global quality of life scores. Standardized mean difference (SMD) with 95% confidence intervals (CI) and risk ratio (RR) with 95% CI were calculated for meta-analysis. RESULTS: We included 41 RCTs involving 3440 participants for analysis. 8 RCTs compared acupuncture with sham acupuncture, among which 3 trials confirmed the biological effects of acupuncture, especially in treating abdominal pain, discomfort, and stool frequency. No significant difference was found when acupuncture was compared with sham acupuncture, in terms of effects on IBS symptoms and quality of life (SMD = 0.18, 95% CI −0.26∼0.63, P=0.42; SMD = −0.10, 95% CI −0.31∼0.11, P=0.35), but the pooled efficacy rate data showed a better outcome for true acupuncture (RR = 1.22, 95% CI 1.01∼1.47, P=0.04), which was not supported by sensitivity analysis. Acupuncture was more effective relative to western medicine in alleviating IBS symptoms (RR = 1.17, 95% CI 1.12∼1.23, I(2) = 0%, P < 0.00001), whose effect might last 3 months. Besides, acupuncture as an adjunct to western medicine, Chinese medications, or tuina was superior over the single latter treatment (RR = 1.68, 95% CI 1.18 to 2.40, P=0.004; 1.19, 1.03 to 1.36, P=0.02; 1.36, 1.08 to 1.72, P=0.009, respectively), with high heterogeneities. CONCLUSIONS: Relative to sham controls, acupuncture showed no superiority for treating IBS, while the advantage over western medicine was significant. Acupuncture could be used as an adjunct in clinical settings to improve efficacy. Future high-quality and large-sample-size studies with adequate quantity-effect design need to be conducted.