Clear Liquids versus Polyethylene Glycol Preparation for Video Capsule Endoscopy of the Small Bowel: A Randomized Controlled Trial

Digestion. 2019;99(3):213-218. doi: 10.1159/000490942. Epub 2018 Sep 13.


Background: An effective bowel cleanse can improve the imaging quality of video capsule endoscopy (VCE). We aimed to further investigate the optimal small bowel cleanse method by comparing the efficacy of 4 L of clear liquids, 2 L of polyethylene glycol (PEG), and 4 L of PEG on the image quality of VCE.

Methods: A randomized controlled, non-inferiority trial was performed comparing 4 L of clear liquids (Group A), 2 L of PEG (Group B), and 4 L of PEG (Group C). The primary endpoint was image quality between the groups. The secondary endpoints included patient tolerability and side effects.

Results: Eighty-one patients were analyzed in group A, 84 patients were analyzed in group B, and 80 patients were analyzed in group C. Image quality scores revealed 4 L of clear liquids to be non-inferior to 2 L of PEG, and 2 L of PEG to be non-inferior to 4 L of PEG (p < 0.0167). Group A had a lower difficulty of completion rate than Group B and Group C and a lower rate of side effects when compared to Group C (p < 0.0167).

Conclusion: Four liters of clear liquids should be considered a routine method for small bowel preparation prior to VCE.

Keywords: Image quality; Preparation; Small Bowel; Video capsule endoscopy.

Publication types

  • Equivalence Trial
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Capsule Endoscopy / adverse effects
  • Capsule Endoscopy / methods*
  • Cathartics / administration & dosage*
  • Cathartics / adverse effects
  • Endoscopy, Gastrointestinal / methods*
  • Female
  • Humans
  • Intestine, Small / diagnostic imaging*
  • Intestine, Small / drug effects
  • Male
  • Middle Aged
  • Nausea / epidemiology
  • Nausea / etiology
  • Polyethylene Glycols / administration & dosage*
  • Polyethylene Glycols / adverse effects
  • Prospective Studies


  • Cathartics
  • Polyethylene Glycols