What Is the Optimal Bowel Preparation for Capsule Colonoscopy and Pan-intestinal Capsule Endoscopy? A Systematic Review and Meta-Analysis

The rate of adequate cleansing (ACR) and complete examinations (CR) are key quality indicators in capsule colonoscopy (CC) and pan-intestinal capsule endoscopy (PCE). To evaluate the efficacy of bowel preparation protocols regarding ACR and CR. We conducted a systematic review and meta-analysis, search terms regarding colon capsule preparation, publication date from 2006/01, and date of search 2021/12, in six bibliographic databases. Multiple steps of the cleansing protocol were assessed: diet, adjunctive laxatives, purgative solution, use of prokinetic agents, and “booster”. The meta-analytical frequency of ACR and CR was estimated, and subgroup analyses performed. Strategies associated with higher ACR and CR were explored using meta-analytical univariable and multivariable regression models. Twenty-six observational studies and five RCTs included ( n = 4072 patients). The pooled rate of ACR was 72.5% (95% C.I. 67.8–77.5%; I 2 = 92.4%), and the pooled rate of CR was 83.0% (95% C.I. 78.7–87.7%; I 2 = 96.5%). The highest ACR were obtained using a low-fibre diet [78.5% (95% C.I. 72.0–85.6%); I 2 = 57.0%], adjunctive laxatives [74.7% (95% C.I. 69.8–80.1%); I 2 = 85.3%], and split dose < 4L polyethylene glycol (PEG) as purgative [77.5% (95% C.I. 68.4–87.8%); I 2 = 47.3%]. The highest CR were observed using routine prokinetics prior to capsule ingestion [84.4% (95% C.I. 79.9–89.2%); I 2 = 89.8%], and sodium phosphate (NaP) as “booster” [86.2% (95% C.I. 82.3–90.2%); I 2 = 86.8%]. In univariable models, adjunctive laxatives were associated with higher ACR [OR 1.81 (95% C.I. 1.13; 2.90); p = 0.014]. CR was higher with routine prokinetics [OR 1.86 (95% C.I. 1.13; 3.05); p = 0.015] and split-dose PEG purgative [OR 2.03 (95% C.I. 1.01; 4.09), p = 0.048]. Main quality outcomes (ACR, CR) remain suboptimal for CC and PCE. Despite considerable heterogeneity, our results support low-fibre diet, use of adjunctive sennosides, split dose < 4L PEG, and routine prokinetics, while NaP remains the most consistent option as booster .