Clinical trial · Interventional
Comparison of Methods to Distend the Colon During Insertion: CO2, Air Insufflation, Water-aided Colonoscopy
Comparison of Methods for Luminal Distention for on Demand Sedation Colonoscopy: Air Insufflation, Carbon Dioxide and Water-aided Colonoscopy. A Randomized Controlled Trial.
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
Insufflation of the colon, usually with room air, is necessary to distend the lumen for exploration. Carbon dioxide (CO2) insufflation instead of room air insufflation (AI) has been shown to decrease symptoms of abdominal pain or discomfort during the procedure and particularly during the following 24 hours. CO2 is is rapidly absorbed by the intestinal mucosa and exhaled through respiration. AI colonoscopy has usually been the reference standard to compare colonoscopy using CO2 insufflation. In two recent articles AI was compared to either CO2 insufflation and Water-aided colonoscopy (WAC), which entails infusion of water to facilitate insertion to the cecum. WAC can be categorized broadly in Water Immersion (WI) and Water Exchange (WE). In WI water is infused during the insertion phase of colonoscopy, with removal of infused water predominantly during withdrawal. Occasional use of insufflation may be allowed. WE entails complete exclusion of insufflation, removal of residual colonic air pockets and feces, and suction of infused water predominantly during insertion to minimize distention. During the withdrawal phase insufflation is used to distend the colonic lumen. In the WAC arms of the two mentioned articles the insertion method used was WI, with infusion of water at room temperature or at 37°C. During withdrawal, air insufflation or either air or CO2 insufflation were employed. Compared to AI, CO2 insufflation and WI (using room air insufflation or CO2 insufflation during withdrawal) were effective in both studies in decreasing sedation requirement, pain and tolerance scores, with patients' higher willingness to repeat the procedure. Until now no direct comparison has been made within a single study about pain score during colonoscopy using AI, CO2 insufflation, WI/CO2, WE/CO2, WI/AI and WE/AI. In this study we test the hypothesis that, compared to AI, CO2 insufflation and WAC/CO2-AI methods will decrease pain score during colonoscopy, with reduction of sedation requirement, and that WE will achieve the best result. This comparative study has also the aim to test the respective peculiarities of each method.
Conditions
Conditions (3)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Colorectal Adenomas | — | UNRESOLVED | — |
| Colorectal Cancer | Malignant Colorectal Neoplasm | CURATED_BROADER | 0.80 |
| Pain | — | UNRESOLVED | — |
Interventions
Interventions (6)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Air Insufflation method. | Other | — | UNRESOLVED |
| CO2 insufflation | Other | — | UNRESOLVED |
| Water Exchange/AI | Other | — | UNRESOLVED |
| Water Exchange/CO2 | Other | — | UNRESOLVED |
| Water Immersion/AI | Other | — | UNRESOLVED |
| Water Immersion/CO2 | Other | — | UNRESOLVED |
Design
Arms and outcomes
Arms (6)
- type
- ACTIVE_COMPARATOR
- label
- Air insufflation method.
- description
- Colonoscopy performed in the standard fashion, with the minimal air insufflation required to aid insertion and allowing for washing as needed. Considered to be standard procedure.
- interventionNames
- Other: Air Insufflation method.
- type
- EXPERIMENTAL
- label
- CO2 insufflation
- description
- Colonoscopy performed with CO2 insufflation using the insufflation unit, allowing for washing as needed.
- interventionNames
- Other: CO2 insufflation
- type
- EXPERIMENTAL
- label
- Water Immersion/CO2
- description
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 18 Years
- Maximum age
- 85 Years
Show eligibility criteria text
Inclusion Criteria: * Consecutive 18 to 85 year-old diagnostic in-patients and outpatients agreeing to start procedure without premedication. Exclusion Criteria: * Patient unwillingness to start the procedure without sedation/analgesia * previous colorectal surgery * proctosigmoidoscopy or bidirectional endoscopy * patient refusal or inability to provide informed consent * inadequate assumption of bowel preparation * moderate or severe chronic obstructive pulmonary disease requiring oxygen * medical history of CO2 retention
References
Publications (8)
- BACKGROUNDFalt P, Liberda M, Smajstrla V, Kliment M, Bartkova A, Tvrdik J, Fojtik P, Urban O. Combination of water immersion and carbon dioxide insufflation for minimal sedation colonoscopy: a prospective, randomized, single-center trial. Eur J Gastroenterol Hepatol. 2012 Aug;24(8):971-7. doi: 10.1097/MEG.0b013e3283543f16. PMID 22569079
- BACKGROUNDAmato A, Radaelli F, Paggi S, Baccarin A, Spinzi G, Terruzzi V. Carbon dioxide insufflation or warm-water infusion versus standard air insufflation for unsedated colonoscopy: a randomized controlled trial. Dis Colon Rectum. 2013 Apr;56(4):511-8. doi: 10.1097/DCR.0b013e318279addd. PMID 23478620
- BACKGROUNDLeung FW, Amato A, Ell C, Friedland S, Harker JO, Hsieh YH, Leung JW, Mann SK, Paggi S, Pohl J, Radaelli F, Ramirez FC, Siao-Salera R, Terruzzi V. Water-aided colonoscopy: a systematic review. Gastrointest Endosc. 2012 Sep;76(3):657-66. doi: 10.1016/j.gie.2012.04.467. PMID 22898423
- BACKGROUNDRabenstein T, Radaelli F, Zolk O. Warm water infusion colonoscopy: a review and meta-analysis. Endoscopy. 2012 Oct;44(10):940-51. doi: 10.1055/s-0032-1310157. Epub 2012 Sep 17. PMID 22987214
- BACKGROUNDLeung FW. Water-aided colonoscopy. Gastroenterol Clin North Am. 2013 Sep;42(3):507-19. doi: 10.1016/j.gtc.2013.05.006. PMID 23931857
- BACKGROUNDWu J, Hu B. The role of carbon dioxide insufflation in colonoscopy: a systematic review and meta-analysis. Endoscopy. 2012 Feb;44(2):128-36. doi: 10.1055/s-0031-1291487. Epub 2012 Jan 23. PMID 22271023
- BACKGROUNDDellon ES, Hawk JS, Grimm IS, Shaheen NJ. The use of carbon dioxide for insufflation during GI endoscopy: a systematic review. Gastrointest Endosc. 2009 Apr;69(4):843-9. doi: 10.1016/j.gie.2008.05.067. Epub 2009 Jan 18. PMID 19152906