Comparing Water Immersion and Water Exchange Methods During Minimally Sedated Colonoscopy

Comparing Air Insufflation, Water Immersion and Water Exchange Methods During Minimal Sedated Colonoscopy, a Randomized, Controlled Trial

In minimally sedated Asian patients in a community setting the investigators showed that a limited volume of water infusion instead of air insufflation in either the rectal sigmoid colon or the whole colon significantly reduced pain score during colonoscopy. Cecal intubation rate was not compromised. The reduction of pain score ranges from 25% to 32 % in our previous studies.1, 2 In contrast, several US reports described the successful use larger volumes of water infused throughout the entire colon in patients undergoing colonoscopy which result in a greater reduction of the pain score, averaging about 56%.3-5 A recent review suggested that the cause of the difference might lies in the timing of water removal.6 Specifically, the investigators group removed the infused water predominantly during withdrawal phase (water immersion) and the U.S. group removed water during insertion phase (water exchange). This prospective, randomized controlled trial compared water exchange or water immersion with traditional air insufflation in patients undergoing minimally sedated colonoscopy. The investigators test the hypothesis that water exchange can reduce more pain than water immersion in the investigators clinical setting.

The maximal pain score during insertion phase of colonoscopy was assessed with 0 to 10 scale VAS score (0: no pain; 10: maximal pain)

Inclusion Criteria: Patients undergoing minimally sedated colonoscopy Exclusion Criteria: Obstructive lesions of the colon, inadequate bowel preparation, allergy to meperidine, massive ascites, past history of partial colectomy, or refusal to provide written informed consent.

Hsieh YH, Lin HJ, Tseng KC. Limited water infusion decreases pain during minimally sedated colonoscopy. World J Gastroenterol. 2011 May 7;17(17):2236-40. doi: 10.3748/wjg.v17.i17.2236.

Leung F, Harker J, Leung J, Siao-Salera R, Mann S, Ramirez F, Friedland S, Amato A, Radaelli F, Paggi S, Terruzzi V, Hsieh Y. Removal of infused water predominantly during insertion (water exchange) is consistently associated with a greater reduction of pain score - review of randomized controlled trials (RCTs) of water method colonoscopy. J Interv Gastroenterol. 2011 Jul;1(3):114-120. doi: 10.4161/jig.1.3.18510. Epub 2011 Jul 1.

Leung J, Mann S, Siao-Salera R, Ransibrahmanakul K, Lim B, Canete W, Samson L, Gutierrez R, Leung FW. A randomized, controlled trial to confirm the beneficial effects of the water method on U.S. veterans undergoing colonoscopy with the option of on-demand sedation. Gastrointest Endosc. 2011 Jan;73(1):103-10. doi: 10.1016/j.gie.2010.09.020.

Leung JW, Mann SK, Siao-Salera R, Ransibrahmanakul K, Lim B, Cabrera H, Canete W, Barredo P, Gutierrez R, Leung FW. A randomized, controlled comparison of warm water infusion in lieu of air insufflation versus air insufflation for aiding colonoscopy insertion in sedated patients undergoing colorectal cancer screening and surveillance. Gastrointest Endosc. 2009 Sep;70(3):505-10. doi: 10.1016/j.gie.2008.12.253. Epub 2009 Jun 24.