Outcome of the efficacy of Chinese herbal medicine for functional constipation: A systematic review and meta-analysis

BACKGROUND: Functional constipation (FC) is a common and chronic gastrointestinal disease and its treatment remains challenging. AIM: To evaluate the efficacy and safety of Chinese herbal medicine (CHM) on efficacy rate, global symptoms, bowel movements and the Bristol Stool Scale score in patients with FC by summarizing current available randomized controlled trials (RCTs). METHODS: RCTs with CHM to treat FC were identified by a systematic search of six databases from inception to October 20, 2020. Two independent reviewers assessed the quality of the included articles and extracted data. Meta-analyses were performed to odds ratio (OR), mean differences (MD) and 95% confidence interval (CI) using random-effects models. Subgroup analyses and sensitivity analyses were used to explore and interpret the sources of heterogeneity. The funnel plot, Begg’s test and Egger’s test were used to detect publication bias. RESULTS: Ninety-seven studies involving 8693 patients were included in this work. CHM was significantly associated with a higher efficacy rate (OR: 3.62, 95%CI: 3.19-4.11, P < 0.00001) less severe global symptoms (OR: 4.03, 95%CI: 3.49-4.65, P < 0.00001) compared with control treatment, with the low heterogeneity between studies (I(2) = 0%, P = 0.76). CHM was also associated with more frequent bowel movements (MD 0.83, 95%CI: 0.67-0.98, P < 0.00001), a lower score on the Bristol Stool Scale (OR: 1.63, 95%CI: 1.15-2.32, P < 0.006), and a not significant recurrence rate (OR: 0.47, 95%CI: 0.22-0.99, P = 0.05). No serious adverse effects of CHM were reported. CONCLUSION: In this meta-analysis, we found that CHM may have potential benefits in increasing the number of bowel movements, improving stool characteristics and alleviating global symptoms in FC patients. However, a firm conclusion could not be reached because of the poor quality of the included trials. Further trials with higher quality are required.