Dose the Saline Reduce the Mucus Production When Water Exchange Colonoscopy is Used?
Condition: Colon Mucous; Colonoscopy
Study type: Interventional

Summary: 
      This is a study to compare the left colon mucus production between carbon dioxide (CO2)
      insufflation and water exchange (WE) colonoscopy in patients that require a routine or repeat
      colonoscopy. There will be four arms in this study: CO2 insufflation (control group 1), WE
      with water infusion (control group 2), WE with 50% saline infusion (study group 1), and WE
      with 25% saline infusion (study group 2). The patient will prepare himself/herself for the
      colonoscopy as per normal instructions and he/she will be given the information for the study
      at that time so that he/she can make a decision to participate in the study. The WE control
      group will use sterile water filling during colonoscope insertion. The study method will use
      saline filling during colonoscopy insertion. This study will confirm if using the saline
      infusion is a better method in reducing mucus production when WE colonoscopy is used.
    

Detailed description: 
      This will be a single-site (Evergreen General Hospital, Taoyuan, Taiwan), blinded
      investigators, prospective randomized controlled trial (RCT). Felix W. Leung (from Sepulveda
      Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hills,
      CA) will be involved in the study design, data analysis, and report preparation, but not in
      patient enrollment. Randomization (CO2, WE with water, WE with 50% saline, WE with 25%
      saline) will be based on computer generated random numbers placed inside opaque sealed
      envelopes. The envelope (in pre-arranged order) will be opened to reveal the code when the
      colonoscopist is ready to insert the endoscope to begin the examination. This will be a
      comparison of two different insertion methods with four arms (CO2 insufflation, WE with
      water, WE with 50% saline, WE with 25% saline) to see which solution used in WE is better in
      reducing mucus production.

      Patients who are willing to participate will sign an informed consent before starting the
      colonoscopy procedure. Randomization will be stratified by investigators and indication of
      colonoscopy (screening, surveillance, or positive fecal immunochemical test). All
      participating patients will receive conscious sedation during the colonoscopic examination.
      Randomization (prepared by statistics consultant) will be carried out by the method of random
      permuted block design (based on computer generated random numbers) with variable block of 3
      and 6.

      Control method: One arm of the study will include colonoscopy with water infusion during
      insertion as the control method. Residual air in the colon will be removed and sterile water
      will be infused to guide insertion through an airless lumen. Infused water will be removed by
      suction, along with residual fecal debris, predominantly during insertion. Another arm of the
      study will include colonoscopy with CO2 insufflation during insertion as an additional
      control method.

      Study method: Two arms of the study will include colonoscopy with saline infusion of
      different strength, i.e., 50% saline and 25% saline, during insertion. Residual air in the
      colon will be removed and saline solution will be infused to guide insertion through an
      airless lumen. Infused saline will be removed by suction, along with residual fecal debris,
      predominantly during insertion.
    

Intervention name(s): CO2; Water; 50% saline; 25% saline
Intervention type(s): Other; Other; Other; Other
Intervention description(s): using CO2 insufflation to help insertion; using water instead of traditional gas to help insertion; using 50% saline solution instead of traditional gas to help insertion; using 25% saline solution instead of traditional gas to help insertion
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Screening
Keywords: Colonoscopy; Colon Mucus; Water Exchange; Saline