Water Exchange Colonoscopy in Elderly Patients: A Prospective Randomized Controlled Trial
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 200
- Locations
- 1
- Primary Endpoint
- Serum inflammatory factors and pain mediators
Study Overview
Brief Summary
Colonoscopy is an important test for detecting colorectal polyps and cancer, but it can cause pain and discomfort, especially in older adults. Traditional colonoscopy uses air to expand the colon. Water exchange colonoscopy uses warm water instead of air, which may reduce pain and make the examination easier. This study compared four colonoscopy methods in patients aged 55 years and older: non-anesthesia water injection, non-anesthesia gas insufflation, anesthesia water injection, and anesthesia gas insufflation. Two hundred participants were randomly assigned to one of the four groups. The study measured pain using a visual analog scale, the time needed to reach the cecum, and blood levels of inflammatory markers (IL-1β, IL-6, and PGE2). The results may help doctors choose a safer and more comfortable colonoscopy method for older patients, especially when anesthesia may not be suitable.
Detailed Description
Background: Colorectal cancer incidence and mortality increase with age, and colonoscopy is essential for screening and managing colorectal polyps. Conventional gas insufflation can cause abdominal distension, pain, and loop formation, particularly in elderly patients who often have relaxed abdominal muscles, elongated colons, and comorbidities that increase anesthesia risk. Water exchange colonoscopy has been reported to reduce pain by using warm water to navigate the colon without full gas distension.
Objective
To evaluate the clinical value of non-anesthesia water exchange colonoscopy in elderly patients and compare it with anesthesia water exchange, non-anesthesia gas insufflation, and anesthesia gas insufflation.
Methods: This was a single-center, prospective, randomized controlled trial that enrolled 200 patients aged 55 years or older undergoing colonoscopy between November 2024 and December 2025. Participants were randomly assigned (1:1:1:1) using a random number table to four groups (n=50 each): non-anesthesia water injection (NW), non-anesthesia gas insufflation (NA), anesthesia water injection (AW), and anesthesia gas insufflation (AA). All procedures were performed by an experienced endoscopist using a high-definition colonoscope (Olympus CF-HQ290I). Bowel preparation used standard polyethylene glycol electrolyte powder. In water injection groups, warm water at 37°C was injected through the biopsy channel during insertion, with suction of gas and fluid as needed. In gas insufflation groups, conventional air insufflation was used. Anesthesia groups received intravenous propofol combined with a small amount of opioid, administered by an anesthesiologist with continuous vital sign monitoring. The non-anesthesia groups received no anesthesia or analgesia.
Outcomes: The primary outcomes included maximum pain score during examination measured by a 10-point visual analog scale (VAS), cecal intubation time (minutes from insertion to identification of the ileocecal landmark), and serum levels of inflammatory and pain mediators (IL-1β, IL-6, and PGE2) measured by ELISA before and during colonoscopy. Non-inferiority of AW versus NW was assessed for inflammatory mediator inhibition using pre-specified margins. Statistical analysis used SPSS 25.0, with one-way ANOVA, Tukey HSD test, chi-square test, and non-inferiority testing; P<0.05 was considered statistically significant.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Screening
- Masking
- None
Eligibility Criteria
- Ages
- 55 Years to 80 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age ≥ 55 years
- •Indications for colonoscopy
- •Signed informed consent form
Exclusion Criteria
- •History of intestinal surgery
- •Severe intestinal stenosis or obstruction
- •Cognitive impairment that precludes cooperation with assessment
Arms & Interventions
Non-anesthesia water injection (NW)
Participants receive water exchange colonoscopy without anesthesia. Warm water at 37°C is injected through the biopsy channel during insertion; gas and fluid are aspirated as needed. No anesthesia or analgesia is administered.
Intervention: Water exchange colonoscopy (Procedure)
Non-anesthesia gas insufflation (NA)
Participants receive conventional gas insufflation colonoscopy without anesthesia. Air is used to expand the intestinal lumen. No anesthesia or analgesia is administered.
Intervention: Gas insufflation colonoscopy (Procedure)
Anesthesia water injection (AW)
Participants receive water exchange colonoscopy under intravenous general anesthesia with propofol and a small quantity of opioid drugs, administered by an anesthesiologist with continuous vital sign monitoring.
Intervention: Water exchange colonoscopy (Procedure)
Anesthesia water injection (AW)
Participants receive water exchange colonoscopy under intravenous general anesthesia with propofol and a small quantity of opioid drugs, administered by an anesthesiologist with continuous vital sign monitoring.
Intervention: Propofol and opioid anesthesia (Drug)
Anesthesia gas insufflation (AA)
Participants receive conventional gas insufflation colonoscopy under intravenous general anesthesia with propofol and a small quantity of opioid drugs, administered by an anesthesiologist with continuous vital sign monitoring.
Intervention: Gas insufflation colonoscopy (Procedure)
Anesthesia gas insufflation (AA)
Participants receive conventional gas insufflation colonoscopy under intravenous general anesthesia with propofol and a small quantity of opioid drugs, administered by an anesthesiologist with continuous vital sign monitoring.
Intervention: Propofol and opioid anesthesia (Drug)
Outcomes
Primary Outcomes
Serum inflammatory factors and pain mediators
Time Frame: Baseline and periprocedural
Change from baseline in serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) measured by ELISA before and during colonoscopy. Used for non-inferiority comparison between non-anesthesia water injection (NW) and anesthesia water injection (AW).
Pain score (VAS)
Time Frame: Periprocedural
Maximum pain level during colonoscopy assessed by the patient using a visual analog scale (VAS, 0-10 points, where 0 indicates no pain and 10 signifies severe pain).
Secondary Outcomes
- Cecal intubation time(Periprocedural)
- Adverse events(Periprocedural)
Investigators
Yongjian Liao
First People's Hospital Of Lin'an District, Hangzhou
First People's Hospital Of Lin'an District, Hangzhou