Cleaning effect and tolerance of 16 bowel preparation regimens on adult patients before colonoscopy: a network meta-analysis.

PURPOSE: Colonoscopy is the gold standard for the diagnosis of colorectal cancer (CRC). Before a colonoscopy, an adequate bowel preparation (BP) is required. Currently, more novel regimens with different effects have been proposed and used successively. This network meta-analysis aims to compare the cleaning effects and patients' tolerability of several BP regimens.

METHODS: We performed a network meta-analysis of randomized controlled trials including sixteen kinds of BP regimens. We searched PubMed, Cochrane Library, Embase, and Web of Science databases. The outcomes of this study were bowel cleansing effect and tolerance.

RESULTS: We included a total of 40 articles with 13,064 patients. For the primary outcomes, polyethylene glycol (PEG) + ascorbic acid (Asc) + simethicone (Sim) (OR, 14.27, 95%CrI, 2.68-127.87) regimen is ranked first in Boston Bowel Preparation Scale (BBPS). PEG + Sim (OR, 2.0, 95%CrI 0.64-6.4) regimen is ranked first in Ottawa Bowel Preparation Scale (OBPS), but without significant differences. For the secondary outcomes, PEG + Sodium Picosulfate/Magnesium Citrate (SP/MC) (OR, 4.88e + 11, 95%CrI, 39.56-1.82e + 35) regimen is the best in cecal intubation rate(CIR). PEG + Sim (OR,1.5, 95%CrI, 1.0-2.2) regimen is ranked first in adenoma detection rate(ADR). Senna (OR, 3.23, 95%CrI, 1.04-9.97) and SP/MC (OR, 249.91, 95%CrI, 78.49-958.19) regimens are ranked first in abdominal pain and willingness to repeat, respectively. There is no significant difference in cecal intubation time (CIT), polyp detection rate (PDR), nausea, vomiting, and abdominal bloat.

CONCLUSION: PEG + Asc + Sim regimen is more effective at cleaning the bowel. PEG + SP/MC will be helpful to increase CIR. For ADR, PEG + Sim regimen will be more helpful. In addition, PEG + Asc + Sim is the least likely to cause abdominal bloat, while Senna regimen is more likely to cause abdominal pain. Patients prefer to re-use the SP/MC regimen for bowel preparation.