Low-volume polyethylene glycol and bisacodyl for bowel preparation prior to colonoscopy: a meta-analysis

Background: Quality of bowel preparation prior to colonoscopy is essential. Studies have shown a reduced volume of polyethylene glycol (PEG) with bisacodyl may improve visualization and tolerability, but results have varied. Therefore, a meta-analysis was performed to analyze the efficacy of a low-volume PEG bowel preparation with bisacodyl for bowel preparation prior to colonoscopy.

Methods: Multiple databases were searched (June 2012). Only randomized controlled trials in peer-reviewed journals on adult subjects comparing low-volume PEG (2 L) with bisacodyl versus 4 L PEG were included. Meta-analysis for the efficacy of low-volume PEG with bisacodyl and 4 L PEG were analyzed by calculating pooled estimates of number of satisfactory, excellent, and poor bowel preparations as well as adverse patient events (abdominal pain, nausea, vomiting, bloating).

Results: Six studies (N=1,540) met the inclusion criteria. No statistically significant differences were noted between low-volume PEG (2 L) with bisacodyl and 4 liters PEG for number of satisfactory (OR 0.86; 95% CI: 0.45-1.63, P=0.64), excellent (OR 1.08; 95% CI: 0.78-1.50, P=0.63), or poor bowel preparations (OR 0.68; 95% CI: 0.35-1.34, P=0.27). A statistically significant decrease in nausea (OR 0.57; 95% CI: 0.36-0.89, P=0.01), vomiting (OR 0.57; 95% CI: 0.40-0.81, P<0.01), and bloating (OR 0.65; 95% CI: 0.49-0.87, P<0.01) was noted for the low-volume PEG with bisacodyl as compared to 4 L PEG. No statistically significant differences were noted between the two groups for abdominal pain (P=0.62).

Conclusion: Low-volume PEG (2 L) with bisacodyl demonstrates less nausea, vomiting, and bloating without adversely affecting the bowel preparation.