Colorectal Cancer ScreeningFSWNCT03208283
Evaluation of the Impact of Water Method During Insertion Phase of Flexible Sigmoidoscopy in Training
A study testing Water method group and Air insufflation group in people with Colorectal Cancer Screening, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
Colonoscopy is a sedated procedure traditionally performed using air insufflation during the insertion phase of the procedure. Recently, the use of water method (eg, water infusion or water exchange techniques) during the insertion phase of colonoscopy has been reported to increase the proportion of patients in whom… Read more about this study
- Who is it for?
- Ages 50 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Colorectal Cancer Screening
- What is being tested?
- Water method group and Air insufflation group
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 408 participants
- Where
- 1 siteHong Kong
- Study dates
- 28 Oct 2014to Dec 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Consecutive asymptomatic patients suitable for CRC screening by FS
- Age 50 - 70 years
- Written informed consent available
Who cannot join
- Contraindications for endoscopy due to comorbidities
- Unable to provide written informed consent
- Personal history of polyposis syndrome, personal history of CRC, personal history of inflammatory bowel disease
- Coagulopathy (INR>1.5) or thrombocytopenia (platelets <50,000)
- Pregnant patients
Trial locations and contacts
1 site in 1 country.
Hong Kong1 site
Centre for Digestive Health, Institute of Digestive Disease, Chinese University of Hong Kong
Hong Kong
About this study
Official title: Evaluation of the Impact of Water Metsertion Phase of Flexible Sigmoidoscopy in the Training of Primary Care Doctors or Nurse Endoscopists for Colorectal Cancer Screening: A Randomized Controlled Study (FSW Study)
Colonoscopy is a sedated procedure traditionally performed using air insufflation during the insertion phase of the procedure. Recently, the use of water method (eg, water infusion or water exchange techniques) during the insertion phase of colonoscopy has been reported to increase the proportion of patients in whom complete unsedated colonoscopy could be achieved, reduce patient recovery time burdens, decrease abdominal discomfort during and after colonoscopy, enhance cecal intubation, and increase willingness to repeat an unsedated colonoscopy. However, there has been no study on the use of water method during the training of primary care doctors or nurse endoscopists in flexible sigmoidoscopy for colorectal cancer screening.
In unsedated endoscopic procedure such as FS, endoscope insertion techniques that can potentially reduce patient discomfort and increase the rate of achieving an adequate depth of scope insertion are desirable. Our current study aims to evaluate the impact of water method during insertion phase of FS in the training of primary care doctors or nurse endoscopists for colorectal cancer screening.
Read the detailed description
It is estimated that there are about 1.2 million patients with colorectal cancer (CRC) worldwide, with a rising trend in CRC incidence and mortality globally. In Hong Kong, colorectal cancer ranks first in cancer incidence and second in cancer mortality.
CRC is one of the most preventable cancers because its development in general follows an adenoma-carcinoma sequence. Adenomas are considered precursor lesions for CRC. Recent guidelines from USA, Europe and Asia Pacific region recommend CRC screening for average-risk asymptomatic individuals starting at age 50. Modalities such as guaiac-based fecal occult blood tests (gFOBT), fecal immunochemical tests (FIT), flexible sigmoidoscopy, and colonoscopy are among the acceptable options for CRC screening. Studies have shown that early detection and removal of colorectal adenoma by screening flexible sigmoidoscopy (FS) and screening colonoscopy with polypectomy reduce CRC incidence and mortality.
Approximately two-thirds of CRC are located in the sigmoid colon and rectum, which can be diagnosed by FS. In countries where colonoscopy may not be widely available or a prolonged waiting time exists, FS becomes an attractive option for CRC screening.
When compared to colonoscopy, FS has the advantages of being an unsedated procedure, requiring less stringent bowel prep, and being less technically demanding. While flexible sigmoidoscopy have traditionally been performed by gastroenterologists or surgeons, studies have demonstrated that adequately trained primary care doctors and nurse endoscopists can perform screening flexible sigmoidoscopy as safely and effectively as gastroenterologists or surgeons. The American Society for Gastrointestinal Endoscopy (ASGE), the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), and the The Society of Gastrointestinal Nurses and Associates (SGNA) recommend 25 supervised procedures for training in FS. Hawes R et al reported that at least 30 supervised procedures were needed before 85% - 90% of the procedures were graded as competent in doctors without prior experience on rigid sigmoidoscopy. In another report, at least 50 supervised procedures have been suggested for FS training of clinicians without prior endoscopic skills.
From a technical standpoint, colonoscopy is a sedated procedure traditionally performed using air insufflation during the insertion phase of the procedure. Recently, the use of water method (eg, water infusion or water exchange techniques) during the insertion phase of colonoscopy has been reported to increase the proportion of patients in whom complete unsedated colonoscopy could be achieved, reduce patient recovery time burdens, decrease abdominal discomfort during and after colonoscopy, enhance cecal intubation, and increase willingness to repeat an unsedated colonoscopy. However, there has been no study on the use of water method during the training of primary care doctors or nurse endoscopists in flexible sigmoidoscopy for colorectal cancer screening.
In unsedated endoscopic procedure such as FS, endoscope insertion techniques that can potentially reduce patient discomfort and increase the rate of achieving an adequate depth of scope insertion are desirable. Our current study aims to evaluate the impact of water method during insertion phase of FS in the training of primary care doctors or nurse endoscopists for colorectal cancer screening.
- Conditions
- Colorectal Cancer Screening
- Being tested
- Water method group, Air insufflation group
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Water method groupDiagnostic test
Also called Water Immersion
During the insertion phase of the initial 30 FS procedures, sterile water will be infused by a standard endoscopy water pump into the distal colon to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Air insufflation will not be used during the insertion phase. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa.
Air insufflation groupDiagnostic test
Also called Air insufflation
During the insertion phase of the initial 30 FS procedures, air insufflation will be used to allow passage of endoscope to at least 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa.
| Study group | Role | What they receive |
|---|---|---|
| Air insufflation group | Active comparator | During the insertion phase of the initial 30 FS procedures, air insufflation will be used to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa. Receives: Diagnostic Test: Air insufflation group |
| Water method group | Active comparator | During the insertion phase of the initial 30 FS procedures, sterile water will be infused by a standard endoscopy water pump into the distal colon to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Air insufflation will not be used during the insertion phase. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa. Receives: Diagnostic Test: Water method group |
What is being measured
The primary outcome is the main question the study is designed to answer.
Independently performed flexible sigmoidoscopy completion rate by each trainee
The percentage of unassisted FS procedure completed within the allowed 10 minutes in the initial 30 FS procedures for each trainee endoscopist
Measured: 12 weeks
The mean independently performed flexible sigmoidoscopy completion rate in each study group
- The mean percentage of unassisted FS procedure completed within the allowed 10 minutes in the initial 30 FS procedures by all trainee endoscopists in the air insufflation group, and the water method group, respectively
Measured: 12 weeks
Secondary outcomes (4)
Polyp detection rate
Number and type of polyp detected during flexible sigmoidoscopy
Measured: 12 weeks
Insertion distance
Mean unassisted scope insertion distance within the allowed 10 minutes and the total insertion distance in the initial 30 FS procedures
Measured: 12 weeks
Procedural time
Mean insertion time, withdrawal time, and total procedure time in the initial 30 FS in each study group
Measured: 12 weeks
Patients' satisfaction
This will be assessed by validated patient satisfaction questionnaire for gastrointestinal endoscopy (modified GHAA-9)
Measured: 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jul 2017
- Study start28 Oct 2014
- Primary completionDec 2023
- Study completionDec 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Colorectal Cancer ScreeningStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 408 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Raymond Shing Yan Tang, Chinese University of Hong Kong
- Investigators
- Shing Yan Raymond Tang, Principal investigator, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03208283
- Sponsor's protocol ID
- FSW
- Acronym
- FSW
- Status last verified
- Jul 2026
- First submitted
- 15 May 2017
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Impact of Water Metsertion Phase of Flexible Sigmoidoscopy in the Training of Primary Care Doctors or Nurse Endoscopists for Colorectal Cancer Screening: A Randomized Controlled Study (FSW Study)
- ClinicalTrials.gov ID
- NCT03208283
- Acronym / sponsor ID
- FSW / FSW
- Conditions
- Colorectal Cancer Screening
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 408 participants (actual)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 28 Oct 2014 (actual)
- Primary completion
- Dec 2023 (actual)
- Study completion
- Dec 2023 (actual)
- First posted
- 5 Jul 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Colonoscopy is a sedated procedure traditionally performed using air insufflation during the insertion phase of the procedure. Recently, the use of water method (eg, water infusion or water exchange techniques) during the insertion phase of colonoscopy has been reported to increase the proportion of patients in whom complete unsedated colonoscopy could be achieved, reduce patient recovery time burdens, decrease abdominal discomfort during and after colonoscopy, enhance cecal intubation, and increase willingness to repeat an unsedated colonoscopy. However, there has been no study on the use of water method during the training of primary care doctors or nurse endoscopists in flexible sigmoidoscopy for colorectal cancer screening.
In unsedated endoscopic procedure such as FS, endoscope insertion techniques that can potentially reduce patient discomfort and increase the rate of achieving an adequate depth of scope insertion are desirable. Our current study aims to evaluate the impact of water method during insertion phase of FS in the training of primary care doctors or nurse endoscopists for colorectal cancer screening.
Detailed description
It is estimated that there are about 1.2 million patients with colorectal cancer (CRC) worldwide, with a rising trend in CRC incidence and mortality globally. In Hong Kong, colorectal cancer ranks first in cancer incidence and second in cancer mortality.
CRC is one of the most preventable cancers because its development in general follows an adenoma-carcinoma sequence. Adenomas are considered precursor lesions for CRC. Recent guidelines from USA, Europe and Asia Pacific region recommend CRC screening for average-risk asymptomatic individuals starting at age 50. Modalities such as guaiac-based fecal occult blood tests (gFOBT), fecal immunochemical tests (FIT), flexible sigmoidoscopy, and colonoscopy are among the acceptable options for CRC screening. Studies have shown that early detection and removal of colorectal adenoma by screening flexible sigmoidoscopy (FS) and screening colonoscopy with polypectomy reduce CRC incidence and mortality.
Approximately two-thirds of CRC are located in the sigmoid colon and rectum, which can be diagnosed by FS. In countries where colonoscopy may not be widely available or a prolonged waiting time exists, FS becomes an attractive option for CRC screening.
When compared to colonoscopy, FS has the advantages of being an unsedated procedure, requiring less stringent bowel prep, and being less technically demanding. While flexible sigmoidoscopy have traditionally been performed by gastroenterologists or surgeons, studies have demonstrated that adequately trained primary care doctors and nurse endoscopists can perform screening flexible sigmoidoscopy as safely and effectively as gastroenterologists or surgeons. The American Society for Gastrointestinal Endoscopy (ASGE), the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), and the The Society of Gastrointestinal Nurses and Associates (SGNA) recommend 25 supervised procedures for training in FS. Hawes R et al reported that at least 30 supervised procedures were needed before 85% - 90% of the procedures were graded as competent in doctors without prior experience on rigid sigmoidoscopy. In another report, at least 50 supervised procedures have been suggested for FS training of clinicians without prior endoscopic skills.
From a technical standpoint, colonoscopy is a sedated procedure traditionally performed using air insufflation during the insertion phase of the procedure. Recently, the use of water method (eg, water infusion or water exchange techniques) during the insertion phase of colonoscopy has been reported to increase the proportion of patients in whom complete unsedated colonoscopy could be achieved, reduce patient recovery time burdens, decrease abdominal discomfort during and after colonoscopy, enhance cecal intubation, and increase willingness to repeat an unsedated colonoscopy. However, there has been no study on the use of water method during the training of primary care doctors or nurse endoscopists in flexible sigmoidoscopy for colorectal cancer screening.
In unsedated endoscopic procedure such as FS, endoscope insertion techniques that can potentially reduce patient discomfort and increase the rate of achieving an adequate depth of scope insertion are desirable. Our current study aims to evaluate the impact of water method during insertion phase of FS in the training of primary care doctors or nurse endoscopists for colorectal cancer screening.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Air insufflation group | Active comparator | Diagnostic Test: Air insufflation groupDuring the insertion phase of the initial 30 FS procedures, air insufflation will be used to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa. |
| Water method group | Active comparator | Diagnostic Test: Water method groupDuring the insertion phase of the initial 30 FS procedures, sterile water will be infused by a standard endoscopy water pump into the distal colon to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Air insufflation will not be used during the insertion phase. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa. |
Who may qualify
- Ages
- 50 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Consecutive asymptomatic patients suitable for CRC screening by FS
- Age 50 - 70 years
- Written informed consent available
Key exclusion criteria (5 listed)
- Contraindications for endoscopy due to comorbidities
- Unable to provide written informed consent
- Personal history of polyposis syndrome, personal history of CRC, personal history of inflammatory bowel disease
- Coagulopathy (INR>1.5) or thrombocytopenia (platelets <50,000)
- Pregnant patients
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Water method groupAlso: Water ImmersionDuring the insertion phase of the initial 30 FS procedures, sterile water will be infused by a standard endoscopy water pump into the distal colon to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Air insufflation will not be used during the insertion phase. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa. | Diagnostic test | Water method group |
| Air insufflation groupAlso: Air insufflationDuring the insertion phase of the initial 30 FS procedures, air insufflation will be used to allow passage of endoscope to at least 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa. | Diagnostic test | Air insufflation group |
Primary outcome
Independently performed flexible sigmoidoscopy completion rate by each trainee
Time frame: 12 weeks
The percentage of unassisted FS procedure completed within the allowed 10 minutes in the initial 30 FS procedures for each trainee endoscopist
The mean independently performed flexible sigmoidoscopy completion rate in each study group
Time frame: 12 weeks
2) The mean percentage of unassisted FS procedure completed within the allowed 10 minutes in the initial 30 FS procedures by all trainee endoscopists in the air insufflation group, and the water method group, respectively
4 secondary outcomes
Polyp detection rate
Time frame: 12 weeks
Insertion distance
Time frame: 12 weeks
Procedural time
Time frame: 12 weeks
Patients' satisfaction
Time frame: 12 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Shing Yan Raymond Tang principal investigator
Chinese University of Hong Kong
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Water method group and Air insufflation group in people with Colorectal Cancer Screening, run by Chinese University of Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Independently performed flexible sigmoidoscopy completion rate by each trainee (time frame: 12 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jul 2026.