An interventional study of CO2 insufflation with an abdominal compression device and CO2 insufflation with a sham abdominal compression device in Manual Pressure, Repositioning and Colonoscopy, sponsored by Evergreen General Hospital, Taiwan. Recruiting at 2 sites in Taiwan. Open to participants aged 45 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-11.
Sponsored by Evergreen General Hospital, Taiwan · Not applicable, Interventional, and Prevention
The goal of this trial is to evaluate whether water exchange colonoscopy and CO2-insufflation colonoscopy with an abdominal compression device (Maxbelt me3 type, Nippon Sigmax Co., Tokyo, Japan) can achieve a significantly lower proportion of patients requiring manual abdominal pressure during colonoscopic insertion compared with CO2 insufflation alone.
This will be a three-arm multicenter parallel randomized controlled trial (RCT) designed to compare the frequency of ancillary manual assistance (abdominal pressure and/or position change) between CO2-insufflation colonoscopy with Maxbelt (intervention group), CO2-insufflation colonoscopy with sham device (sham control group), and water exchange (WE) colonoscopy (WE group). Enrolled patients will be randomized in a 1:1:1 ratio to either the intervention, sham control, or WE group. This will be a comparison of three different methods (CO2 with interventional device, CO2 with sham device, WE) to see which one is better at decreasing the need for manual assistance by endoscopy staff during colonoscopic insertion.
This study will be conducted in two hospitals in Taiwan: Evergreen General Hospital at Taoyuan and E-Da Dachange Hospital at Kaohsiung. The Sepulveda Ambulatory Care Center, VAGLAHS, UCLA in the USA will be a non-recruiting participating site. This planned RCT will span 30 months (from June 2024 to November 2026), including 3 months for the initial setup and 3 months for the final analysis. The study site possesses state-of-the-art colonoscopy equipment setups, and the investigators are WE colonoscopy research experts.
Patients aged 45-75 y/o at average risk of colorectal cancer who are willing to participate will sign an informed consent before starting the colonoscopy procedure. Separate parallel randomization will be set up at each site, stratified by investigator and type of colonoscopy (screening, surveillance, or positive fecal immunochemical test result). Mode of sedation will include conscious sedation (fentanyl plus midazolam) or full sedation (propofol with fentanyl plus midazolam) . Randomization will be carried out by computer-generated sequences using a block design (four participants per block).
CO2 with interventional device group: The Maxbelt will be applied around the circumference of the lower abdomen just below the umbilicus based on patient's abdominal circumference. Five sizes of Maxbelt will be employed in this study: XS-size for 55-65 cm circumference, S-size for 65-75 cm circumference, M-size for 75-85 cm circumference, L-size for 85-95 cm circumference, and XL-size for 95-105 cm circumference. Once applied, participants will be asked to assess and confirm that the belt is fastened tightly but not uncomfortably.
CO2 with sham device group: A two-size larger Maxbelt with loose fitting will be used as a sham device: L-size will be used for 55-71 cm circumference, XL-size will be used for 72-88 cm circumference, and 2 XL-size will be used for 89-105 cm circumference.
WE group: The air pump will be turned off during the insertion phase of colonoscopy, while the colon is irrigated with warm-to-touch distilled water or half normal saline using a flushing pump. The WE approach involves the simultaneous infusion of water to facilitate luminal expansion and suction of unclean water during insertion.
377 studies on the registry are indexed under Colonic Polyps; 57 are open to participants now.
This study's planned enrollment of 400 is above the median of 274 across 250 interventional studies indexed under Colonic Polyps.
Browse Colonic Polyps studies →Evergreen General Hospital, Taiwan is the lead sponsor of 11 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Colonoscopic insertion will be performed with CO2 insufflation with assistance by an abdominal compression device.
Device: CO2 insufflation with an abdominal compression device
Colonoscopic insertion will be performed with CO2 insufflation in standard method. A sham abdominal compression device will be used as a sham comparator.
Device: CO2 insufflation with a sham abdominal compression device
Colonoscopic insertion will be performed with water exchange method.
Device: Water exchange colonoscopy
For participants randomized to the intervention group, the back brace support belt, Maxbelt (me3 type, Nippon Sigmax Co., Tokyo, Japan), will be applied around the circumference of the lower abdomen. Five sizes of Maxbelt will be employed in this study. According to the manufacturer, the ultra small-size (XS-size) belt will be used in those patients with an abdominal circumference of 55 cm-65 cm, the small-size (S-size) belt will be used in those patients with an abdominal circumference of 65 cm-75 cm, the medium-size (M-size) belt will be used for a circumference of 75 cm-85 cm, the large-size (L-size) belt will be used for a circumference of 85 cm-95 cm, and the ultra large-size (XL-size) will be used for a circumference of 95 cm-105 cm. Once applied, participants will be asked to assess and confirm that the belt is fastened tightly but not uncomfortably.
The study coordinator will fit the sham device in a private bay alone with the patient. For participants randomized to the sham control group, a larger-sized Maxbelt with loose fitting will be used as a sham device. The L-size Maxbelt will be used in those patients with an abdominal circumference of 55 cm-71 cm, the XL-size Maxbelt will be used in in those patients with an abdominal circumference of 72 cm-88 cm, and the 2 XL-size Maxbelt will be used in in those patients with abdominal circumference 89 cm-105 cm.
In those patients assigned to the water exchange (WE) group, the air pump will be turned off during the insertion phase of colonoscopy, while the colon is irrigated with warm-to-touch distilled water or half normal saline using a flushing pump. The WE approach involves the simultaneous infusion of water to facilitate luminal expansion and suction of unclean water during insertion. Any encountered air pockets will be aspirated to ensure optimal WE maneuvers in salvage cleaning.
Frequency of manual pressure
The proportion of patients who need at least one application of manual abdominal pressure during colonoscopic insertion.
Time frame: One day
Frequency of repositioning
The proportion of patients who need at least one application of position change during colonoscopic insertion.
Time frame: One day
Ergonomic pain of after colonoscopy
The musculoskeletal pain experienced by the assisting nurse will be reported based on a 5-point visual analogue scale score immediately after a procedure by using a questionnaire.
Time frame: One day
Colonoscopy difficulty
The colonoscopy difficulty assessed by the endoscopist will be reported using a 5-point visual analogue scale score immediately after completion of the procedure by using a questionnaire.
Time frame: One day
Post-colonoscopy abdominal pain
The pain experienced by the patient will be recorded in the recovery room post-procedure via a questionnaire using a 5-point visual analogue scale score.
Time frame: One day
Cecal intubation time
The cecal intubation time is defined as the time spanning from anal insertion to colonoscopic intubation of cecum.
Time frame: One day
Withdrawal time
The withdrawal time is defined as the time spanning from cecal intubation to colonoscope withdrawal from the anus.
Time frame: One day
Adenoma detection rate
The proportion of patients with at least one conventional adenoma of any size.
Time frame: One week (after the colonoscopy procedure, when pathology report is released)
Plan to share: No
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Evergreen General Hospital, Taiwan