Water infusion for cecal intubation increases patient tolerance, but does not improve intubation of unsedated colonoscopies

Clin Gastroenterol Hepatol. 2011 Dec;9(12):1039-43.e1. doi: 10.1016/j.cgh.2011.06.031. Epub 2011 Jul 13.


Background & aims: Several studies have indicated that water infusion, instead of air insufflation, enhances cecal intubation in selected patients undergoing unsedated colonoscopy. We performed a prospective, randomized, controlled trial to investigate whether the water technique increases the proportion of patients that are able to complete unsedated colonoscopy.

Methods: We analyzed data from 116 consecutive outpatients who were willing to start colonoscopy without sedation; 58 were each randomly assigned to groups given water infusion or air insufflation during the insertion phase. Sedation and analgesia were administered on demand.

Results: Fewer patients requested sedation in the water group (8.6%) than in the air group (34.5%; P = .003) and their maximum pain scores were lower (2.8 ± 1.9 vs 4.2 ± 2.3 in the air group; P = .011). However, differences in percentages of patients who received complete, unsedated colonoscopy between the water group (74.1%) and air group (62.1%) did not reach statistical significance (P = .23); the percentage of successful cecal intubations was lower in the water group (82.8%) than in the air group (96.5%; P = .03) because of poor visibility. Failed procedures in the water group were completed successfully after air insufflation. The cecal intubation time was shorter in the air group (6.2 ± 3.4 min) than in the water group (8.1 ± 3.0 min; P = .01).

Conclusions: In patients willing to undergo unsedated colonoscopy, water infusion improves patient tolerance for cecal intubation, compared with air insufflation. However, it does not increase the overall percentage of successful cecal intubations because suboptimal bowel preparation interferes with visibility.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Air
  • Colonoscopy / methods*
  • Female
  • Humans
  • Hypnotics and Sedatives / administration & dosage*
  • Insufflation / methods
  • Intubation / methods*
  • Male
  • Middle Aged
  • Prospective Studies
  • Water


  • Hypnotics and Sedatives
  • Water