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Bowel preparation with still water for small bowel capsule endoscopy: Less is more
Ana I Ferreira, Francisca Côrte-Real, Mariana M Souto, Sofia Xavier, José R Pereira, Cátia Arieira, Bruno Rosa, Maria A Duarte, José Cotter
Ana I Ferreira, Mariana M Souto, Sofia Xavier, Cátia Arieira, Bruno Rosa, José Cotter, Department of Gastroenterology, Unidade Local de Saúde do Alto Ave, Guimarães 4835-044, Portugal
Ana I Ferreira, Mariana M Souto, Sofia Xavier, Cátia Arieira, Bruno Rosa, José Cotter, Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga 4710-057, Portugal
Ana I Ferreira, Mariana M Souto, Sofia Xavier, Cátia Arieira, Bruno Rosa, José Cotter, ICVS/3B’s, PT Government Associate Laboratory, Braga 4710-057, Portugal
Francisca Côrte-Real, José R Pereira, Maria A Duarte, Department of Gastroenterology, Hospital do Divino Espírito Santo de Ponta Delgada (HDES), Ponta Delgada 9500-370, Portugal
Author contributions: Ferreira AI performed the analysis and wrote the first draft of the manuscript; Ferreira AI and Côrte-Real F performed material preparation and data collection; Ferreira AI, Côrte-Real F, Souto MM, Xavier S, and Rosa B contributed to the study conception and design; Xavier S, Pereira JR, Arieira C, Rosa B, Duarte MA, and Cotter J commented on previous versions of the manuscript, read and approved the final manuscript.
Institutional review board statement: The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a priori approval by the Institutional Review Board of Unidade Local de Saúde do Alto Ave (No. 42/2023) and the Institutional Review Board of the Hospital do Divino Espírito Santo de Ponta Delgada (No. S-HDES/2024/662).
Clinical trial registration statement: The manuscript has been registered.
Informed consent statement: All participants provided informed consent.
Conflict-of-interest statement: All authors declare no conflict of interest in publishing the manuscript.
CONSORT 2010 statement: The authors have read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
Data sharing statement: No additional data are available.
Corresponding author: Ana I Ferreira, MD, Department of Gastroenterology, Unidade Local de Saúde do Alto Ave, R. Dos Cutileiros 114, Creixomil, Guimarães 4835-044, Portugal.
ai.voferreira@gmail.com
Received: December 5, 2025
Revised: January 4, 2026
Accepted: May 21, 2026
Published online: June 16, 2026
Processing time: 187 Days and 7.8 Hours
BACKGROUND
The optimal bowel preparation for small bowel capsule endoscopy (SBCE) has not been standardized.
AIM
To compare the rate of complete examinations, quality of bowel preparation, diagnostic yield and tolerability, using three protocols for SBCE.
METHODS
A prospective, multicentre, randomized study including patients submitted to SBCE was conducted. Patients ingested a booster once the capsule reached the small bowel, randomized into one of three protocols: (1) 1 L of polyethylene glycol (PEG); (2) 1 L of PEG and ascorbic acid; and (3) 1 L of water. The patients’ bowel preparation was evaluated with Small Bowel CLEansing Assessment and Report.
RESULTS
A total of 261 patients were included, 96 (36.8%) in protocol 1, 93 (35.6%) in protocol 2 and 72 (27.6%) in protocol 3. The rate of complete examinations, adequate bowel preparation and diagnostic yield were comparable among the groups (P = 0.655, P = 0.193 and P = 0.589, respectively). The overall Small Bowel CLEansing Assessment and Report score was similar among the protocols (P = 0.236). Although the preparation of the third tertile had a lower score using protocol 3 (protocol 1: 2.5 ± 0.1 vs 2: 2.6 ± 0.1 vs 3: 2.3 ± 0.1, P = 0.021), it did not compromise the mucosal visualization, maintaining a mean score above 2 and similar diagnostic yield among the protocols (P = 0.850). The patients’ reported tolerability was higher in protocol 3 (protocol 1: 2.8 ± 0.1 vs 2: 3.0 ± 0.2 vs 3: 0.6 ± 0.1, P < 0.001).
CONCLUSION
Using 1 L of water as a booster in SBCE was better tolerated and associated with comparable rates of complete examinations, adequate bowel preparation and diagnostic yield vs PEG with or without ascorbic acid.
Core Tip: This prospective, multicentre, randomized study compared complete examination rates, bowel preparation quality, diagnostic yield, and tolerability across three small-bowel capsule endoscopy protocols. A total of 261 patients from two Portuguese university-affiliated hospitals were included. After the capsule reached the small bowel, patients received one of three boosters: (1) 1 L of polyethylene glycol; (2) 1 L of polyethylene glycol plus ascorbic acid; and (3) 1 L of water. Outcomes were similar across groups, with higher tolerability in protocol 3. Thus, using 1 L of water as a booster was better tolerated without reducing examination completeness, bowel preparation quality, or diagnostic yield.
