Colon capsule endoscopy (CCE) offers a minimally invasive alternative to conventional colonoscopy, yet its clinical impact is strictly dependent on achieving adequate colon cleansing rates (ACR) and completion rates (CR). These requirements impose more stringent preparatory demands than traditional colonoscopy, as capsules cannot rinse or flush the lumen. Existing systematic reviews (SRs) and meta-analyses (MAs) on CCE procedure laxatives and boosters’ regimens show significant variability in recommendations and methodological rigor, creating a barrier to clinical practice harmonization. The aim of this umbrella review is to synthesize and critically appraise findings from existing SRs/MAs to evaluate the comparative effectiveness of CCE bowel preparation strategies, and identify areas of consensus and uncertainty.

A literature search to November 2025 identified SRs/MAs evaluating preparation regimens for CCE. Methodological quality was assessed using AMSTAR-2. Primary study overlap was quantified using the Corrected Covered Area (CCA). Primary outcomes were ACR and CR; data were stratified by regimen components (laxatives, boosters, prokinetics, diet) and specific populations. AI assistance (Google Gemini 3 Pro) was used for data organization.

Fourteen SRs (comprising 11 MAs) including 102 unique primary studies and over 16,000 patients were included. The CCA was 8.59%, indicating moderate overlap and confirming that reviews provide complementary evidence. Methodological quality was variable, with only two reviews rated as high quality, while the majority were classified as low or critically low due to reporting limitations. Overall pooled ACR (72.5%–76.8%) and CR (79.8%–83.0%) remained suboptimal compared to colonoscopy standards. In patients with Inflammatory Bowel Disease (IBD), efficacy varied widely (ACR 49–98.5%) with no significant difference between regimens. However, component analysis identified superior strategies: low-volume polyethylene glycol (PEG, <4L) yielded numerically higher ACR (77.5%) compared to high-volume regimens (72.9%). Sodium phosphate (NaP) boosters consistently outperformed PEG boosters, with the NaP + Gastrografin combination achieving the highest absolute CR (93.1%). Castor oil significantly improved excretion rates (92% vs 73%), and routine prokinetics were superior to selective use (OR 1.86). Finally, a low-fiber diet was associated with better cleansing than a clear liquid diet (ACR 78.5% vs 70.0%).

CCE bowel preparation regimens frequently result in suboptimal CR and ACR, highlighting the need for protocol standardization. Meta-analytic evidence consistently demonstrates that the optimization of regimens by combining low-volume PEG, NaP-based or Gastrografin boosters, and routine prokinetics yield superior outcomes, though specific needs may vary in IBD populations. The substantial heterogeneity across reviews, driven by variable definitions and protocols, underscores the need for consensus. The 2025 Nyborg Consensus recommendations, such as the adoption of the CC-CLEAR scale and mandatory reporting fields, are critical next steps. Since ACR and CR are significant inverse predictors of follow-up endoscopy rates, the future adoption of optimized and personalized protocols is crucial for cost-effectiveness.