Neoplasms

All Conditions

Symptoms and General Pathology

Adenoma

Polyps

Neoplasms, Glandular and Epithelial

Neoplasms by Histologic Type

Water exchange (WE) method was used for insertion to the cecum.

Air insufflation (AI) method was used for insertion to the cecum.

Water exchange (WE) method was used for insertion to the cecum. And air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal procedure.

Water exchange (WE) method

Air insufflation (AI) method was used for insertion to the cecum. And air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal procedure.

Air insufflation (AI) method.

Gui Ren, MD

Yanglin Pan, MD

Patients with colorectal adenomas are suggested to receive polypectomy. A substantial number of adenomas may be missed in patients with polyps found by previous colonoscopy. And water exchange (WE) method may increase the detection of missed adenoma compared with traditional air insufflation (AI) colonoscopy. The investigators aim to investigate whether water exchange colonoscopy method, compared with air insufflation method, can improve the detection of missed adenomas in patients undergoing selective polypectomy.

For WE method, the air pump was turned off for the full duration of insertion to avoid inadvertent air insufflations and colon elongation. Residual air in the lumen was suctioned to minimize angulations at flexures. Water at 37°C was infused with a pump (Olympus) through the biopsy channel to confirm correct tip orientation for scope advancement. The infused water was removed predominantly by suction when the colonoscope was smoothly advanced during the insertion phase, and turbid luminal water due to residual feces was exchanged by clean water until the lumen was clearly visualized. Occasionally, if it was difficult to determine whether the colonoscope tip was in the cecum, air was allowed to be insufflated for observation. If the position of the scope tip was confirmed to be not in the cecum, insufflated air would be removed by suction and the WE method would be continuously used until successful intubation.

For the AI method, water was not used, and air was insufflated during insertion.

Air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal for both methods. Polyps will be removed by forceps biopsy (polyps size \<3mm), cold snare technique (3-6mm) or endoscopic mucosal resection (size≥6mm).

Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy

Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy: a Single-centered, Randomized Controlled Study

Adenoma miss rate was calculated as the number of patients with one and more additional adenomas during polypectomy procedure divided by the total number of patients in each group.

Adenoma-level miss rate was calculated as the number of additional adenomas detected in polypectomy procedure divided by the total number of adenomas in each group.

Advanced adenoma: any with 3 or more adenomas of any size, 1 or more large adenomas 1 cm, or 1 or more adenomas with villous architecture or highgrade dysplasia.

The mean number of adenoma per positive patient

The Boston Bowel Preparation Scale (BBPS): cleanliness of each part of the colon: 0=unprepared colon segment with mucosa not seen because of solid stool that cannot be cleared; 1=portion of mucosa of the colon segment seen, but other areas of the colon segment not well seen because of staining, residual stool, and/or opaque liquid; 2=minor amount of residual staining, small fragments of stool and/or opaque liquid, but mucosa of colon segment seen well; 3=entire mucosa of colon segment seen well with no residual staining, small fragments of stool, or opaque liquid.

Air Force Military Medical University, China

Associated professor

Anti-Infective Agents

All Drugs and Chemicals

Antineoplastic Agents

Micronutrients

Vitamins

Acetic Acid

Retinol acetate

Vitamin A

Retinol palmitate

Anti-Bacterial Agents

Adjuvants, Immunologic

Immunologic Factors

Protective Agents

Retinol

Water containing 1% of AA was used during insertion of colonoscopy using water exchange method.

Water exchange colonoscopy was used for standard screening or surveillance colonoscopy.

The water exchange colonoscopy is used during insertion procedure, in which the water contains 1% acetic acid, and the liquid is absorbed during the withdrawal process for observation.

acetic acid staining

The water exchange colonoscopy is used during insertion procedure, and the liquid is absorbed during the withdrawal process for observation.

Water exchange colonoscopy

Xiaojun Huang, MD

Xiaoying Zhang, MD

Jianghai Zhao, MD

Limei Wang, MD

Our previous study (Am. J. Gastroenterol. 2017 04;112(4)) showed that water exchange (WE) colonoscopy was able to increase the detection of flat adenomas as well as overall ADR. We hypothesized that WE based whole-colon acetic acid（AA） staining might be useful to improve the detection of flat lesions compared with WE alone.

Water exchange colonoscopy was performed as described previously (Am. J. Gastroenterol. 2017 04;112(4)). Patients were randomly allocated to WE group or WE+AA group. In WE+AA group, water containing 1% of AA was used during insertion of colonoscopy instead of water alone. A bottle of 20ml pure AA was placed abutting the water pump, which make it possible to keep patients blinded to group allocation. Endoscopist using a high-definition wide-angle Olympus or Fujinum colonoscope performed all of the colonoscopies, with a withdrawal time of at least 6 min. The observation was initially performed without the assistance of cap or the use of magnification or electronic staining (NBI, BLI, LCI or AFI et al.). Scopolamine butylbromide or glucogon was not routinely administrated.

Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Colonoscopy

Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Screening and Surveillance Colonoscopy: a Multi-centered, Randomized Controlled Study.

average numbers of flat polyps, defined by Paris classification IIa/IIb/IIc, for each patient

Adenoma detection rate, defined as the proportion of subjects with at least one adenoma of any size, in each group.

Advanced adenoma detection rate. Advanced adenoma: any with 3 or more adenomas of any size, 1 or more large adenomas 1 cm, or 1 or more adenomas with villous architecture or highgrade dysplasia.

SSA/P detection rate, defined as the proportion of subjects with at least one sessile serrated adenoma/polyp (SSA/P) of any size, in each group.

Low-grade adenoma, adenoma with villous components, high-grade adenoma, noninvasive carcinoma, and invasive carcinoma in proximal colon

the rate of bleeding and perforation during colonoscopy procedure and abdominal pain, diarrhea, hematochezia and change of defecation habit Within one week.

Herbal and Botanical

Cola

During the insertion phase of the first-pass colonoscopy, water exchange (WE) method was used. WE entailed the infusion of water to open the lumen and sequentially suction of water. When the cecum was reached and after most of the water was suctioned to collapse the cecal lumen, CO2 was opened during the withdrawal phase of the first-pass colonoscopy. After the first complete withdrawal of the colonoscope, a second colonoscopic examination aided by CO2 insufflation during insertion and withdrawal was performed by the same endoscopist. The colonoscope was reinserted into the cecum as quickly as possible, and the entire colon was re-examined. Polyp resection was carried out during insertion and withdrawal of the first- and second-pass examinations.

During the first-pass colonoscopy, the procedure was performed in the usual fashion, with minimal CO2 insufflation to aid insertion. Cleaning of colon was predominantly performed during withdrawal. After the first complete withdrawal of the colonoscope, a second colonoscopic examination aided by CO2 insufflation during insertion and withdrawal was performed by the same endoscopist. The colonoscope was reinserted into the cecum as quickly as possible, and the entire colon was re-examined. Polyp resection was carried out during insertion and withdrawal of the first- and second-pass examinations.

During back-to-back colonoscopy, the first examination was completed with water exchange during insertion and CO2 insufflation during withdrawal. The second examination was completed with CO2 insufflation during both the insertion and withdrawal.

During back-to-back colonoscopy, the first examination was completed with CO2 insufflation during both the insertion and withdrawal. The second examination was also completed with CO2 insufflation during both the insertion and withdrawal.

CO2 insufflation colonoscopy

Chi-Liang Cheng

This was an observational study comparing consecutive group of WE and CO2 insufflation in terms of right and proximal colon AMR by tandem colonoscopy.

This was a prospective observational study to assess how WE colonoscopy would fit into clinical and research practices. We first observed whether optimal WE colonoscopy decreased the AMR in the right and proximal colon in a tandem approach. If WE did lower the AMR as compared with data in the literature, a randomized RCT deserves to be studied. For the calculation of sample size in the upcoming RCT, the AMR in the CO2 group would be collected. The differences of the AMRs in the right and proximal colon determined by tandem colonoscopy using WE or CO2 insufflation would then be compared.

Adenoma Miss Rate With Water Exchange vs Carbon Dioxide Colonoscopy

Water Exchange Colonoscopy Decreased Adenoma Miss Rates in the Right and Proximal Colon: An Observational Study Using A Tandem Colonoscopy Approach

Right-colon (cecum, A-colon, hepatic flexure) adenomas detected on the second-pass examination were used for the calculation of adenoma miss. Adenoma miss rate was calculated as the number of adenomas missed in the first colonoscopy divided by the total number of adenomas detected during both the first and second colonoscopies.

Proximal-colon (cecum, A-colon, hepatic flexure, T-colon) adenomas detected on the second-pass examination were used for the calculation of adenoma miss. Adenoma miss rate was calculated as the number of adenomas missed in the first colonoscopy divided by the total number of adenomas detected during both the first and second colonoscopies.

Evergreen General Hospital, Taiwan

M.D.

Water Exchange Colonoscopy

CO2 Insufflation Colonoscopy

During the insertion phase of the first-pass colonoscopy, WE method was used. When the cecum was reached, CO2 was opened during the withdrawal phase of the first-pass colonoscopy. After the first complete withdrawal of the colonoscope, a second colonoscopic examination aided by CO2 insufflation during insertion and withdrawal was performed by the same endoscopist. The colonoscope was reinserted into the cecum as quickly as possible, and the entire colon was re-examined. Polyp resection was carried out during insertion and withdrawal of the first- and second-pass examinations.

Total

Age, Continuous

Sex: Female, Male

Race and Ethnicity were not collected from any participant.

Race and Ethnicity Not Collected

Taiwan

Region of Enrollment

Dr. Chi-Liang Cheng

Percentage of Overall Detected Adenomas Missed During the First Right-Colon Colonoscopy

Percentage of Overall Detected Adenomas Missed During the First Proximal-Colon Colonoscopy

Overall Study

Pain

Colonoscopy will be 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.

Air will not be insufflated until the cecum is reached. It will be allowed only 3 times and no more than 10 seconds each time (ITT failure if \>3) if the lumen cannot be seen. Infusion of water during the insertion phase of colonoscopy mainly to open the colonic lumen and progress to the cecum immersed in the water environment thus created, without attempting to clear the colon contents. Residual air in the colon will not be removed. Infused water and residual feces will be suctioned back predominantly during withdrawal.

Air will not be insufflated until the cecum is reached. Infusion of a sufficient amount of water to render the lumen of the colon a slit to progress with the colonoscope. Part of the infused water will be constantly suctioned back exchanging clean for dirty or hazy water. Suction of water will also be applied when colonoscope insertion proceeds smoothly. Air pockets will be always aspirated to collapse the lumen. After cecal intubation as much residual water as possible will be aspirated before beginning the withdrawal phase. During withdrawal residual water and feces will be suctioned.

Air Insufflation method.

Water Immersion method.

Water Exchange method.

Sergio Cadoni, MD

Water-aided method for colonoscopy can be broadly subdivided into two major categories. Water Immersion (WI), characterized by suction removal of the infused water predominantly during the withdrawal phase of colonoscopy, and Water Exchange (WE), characterized by suction removal of infused water predominantly during the insertion phase of colonoscopy. Several studies showed that WE significantly reduces pain compared to WI and colonoscopy with traditional air insufflation (AI), increases the number of unsedated procedures and adenoma detection rate (ADR), in particular proximal ADR. This randomized controlled trial will be a direct comparison of Air Insufflation, Water Immersion and Water Exchange to test the hypothesis that WAC (particularly WE) would significantly decrease pain score during colonoscopy in diagnostic patients. Several other secondary outcomes will also be analyzed.

Introduction Water-aided methods for colonoscopy can be broadly subdivided into two major categories.

Water Immersion (WI) is characterized by suction removal of the infused water predominantly during the withdrawal phase of colonoscopy and Water Exchange (WE) is characterized by suction removal of infused water predominantly during the insertion phase of colonoscopy.

Several studies showed that WE significantly reduces pain compared to WI and colonoscopy with traditional air insufflation (AI), increases the number of unsedated procedures and adenoma detection rate (ADR), in particular proximal ADR. This randomized controlled trial will be a direct comparison of Air Insufflation, Water Immersion and Water Exchange to test the hypothesis that WAC (particularly WE) would significantly decrease pain score during colonoscopy in diagnostic patients. Several other secondary outcomes will also be analyzed.

Method

Examinations will be allocated to Water Exchange, Water Immersion or Air Insufflation during the insertion phase of colonoscopy based on a computer generated random list. Procedures will be started by 6 board-certified endoscopists, three with experience in 8,000-10,000 and three with experience in 2,000-5,000 colonoscopies with AI, 285 with WI and 890 with WE overall.

High-resolution wide-angle variable-stiffness adult video colonoscopes (Olympus HD 180 series; Olympus Corp, Hamburg, Germany) will be used. Need to change to a smaller caliber colonoscope will be considered ITT failure.

Patients will have a low volume split dose bowel preparation with 2L of polyethylene glycol (PEG) solution or Sodium Picosulfate. Investigators will be blinded to the colon preparation used. Before starting the procedure, a questionnaire recording demographic data, previous abdominal surgery, co-morbidities and current medications will be administered by the endoscopists. The patients, but not endoscopists and assisting nurses, will be blinded to the method used. At discharge the patient will be asked to guess which method has been used. If no more than half of the responses are correct, patients' blinding will be considered adequate.

Colonoscopy will begin with the patients in the left lateral position, without premedication. The withdrawal phase will be identical in all arms of the study using air insufflation to obtain adequate distension of the colonic lumen for mucosal inspection, biopsy and/or polypectomy.

Patients randomized to the water-aided colonoscopy group, during the insertion phase after reaching the rectosigmoid junction, will have the colon irrigated with water at 37°C maintained with a water bath. Infusions will be performed using flushing pumps (Olympus OFP2, Olympus, Hamburg, Germany or Velocity irrigation pump, US Endoscopy, OH, USA). There will be no restriction of the overall volume of water that can be infused to get adequate lumen distention and reach the cecum. With the patient in the left lateral position water infused into the colon at the rectal sigmoid junction flows into the descending colon. The weight of the water in the left side of the colon straightens the sigmoid segment increasing the ease of insertion and reducing the risk of loop formation. The air pump will be turned off to avoid inadvertent insufflation.

Water Immersion will involve the infusion of water during the insertion phase of colonoscopy mainly to open the colonic lumen and progress to the cecum immersed in the water environment thus created, without attempting to clear the colon contents. Use of water as an adjunct to air insufflation to facilitate insertion and removal of infused water predominantly during withdrawal are characteristic features of WI. This traditional adjunct facilitates passage through the sigmoid colon with severe diverticulosis, speeds arrival to the splenic flexure, decreases colonic spasm, minimizes pain, and even enhances cecal intubation in previously incomplete colonoscopies.

Residual air in the colon will not be removed. The infused water and residual feces will be suctioned back only during withdrawal. Air insufflation will be allowed if the lumen cannot be seen and the endoscopists judges unsafe to advance the colonoscope. It will last no more than 10 seconds and will be recorded in the patient data sheet. If more than 3 episodes of air insufflation will be recorded the procedure will be considered ITT failure.

Water Exchange will involve complete exclusion of air insufflation, removal of residual colonic air and feces and of infused water predominantly during insertion to assist identification of the lumen. WE minimizes loop formation and decreases discomfort. By providing salvage cleansing during insertion, WE allows the colonoscopist to devote a greater proportion of the withdrawal to inspection. WE will involve the infusion of a sufficient amount of water to open the lumen of the colon to allow passage of the instrument, thus rendering the colonic lumen a slit to progress with the colonoscope. If the lumen does not open, the colonoscope will be slightly retracted and the infusion started again. Part of the infused water will be constantly suctioned back exchanging clean for dirty or hazy water. Suction of infused water will also be applied when colonoscope insertion proceeds smoothly. Air pockets, when encountered, will be always aspirated to collapse the lumen: the absence of air space forces the colonoscopist to use water to clear residual feces and to find the way through the colon. Removal of the air also shortens the colon and takes out all the sharp turns at the flexures and redundant segments, reducing the risk of loop formation: water instillation does not elongate the colon as much as air insufflation does. In a collapsed, airless colon turbulences created at the tip of the instrument facilitate the removal by suction of residual feces adherent to the mucosa. This provides salvage cleansing during the insertion phase. After cecal intubation as much residual water as possible will be aspirated before beginning the withdrawal phase. During withdrawal scarce amounts of water are left to aspirate, and residual water and feces will be suctioned.

In the AI group, colonoscopy will be performed in the standard fashion, allowing for washing as needed. In all groups abdominal compression and position change were applied as needed.

Cecal intubation will be defined as passage of the tip of the colonoscope to a point proximal to the ileocecal valve with adequate visualization of the cecum and appendix orifice. A stopwatch will be used to time the procedures. Cecal intubation time will be defined as the time for passage of the colonoscope from the rectum to the cecum. The withdrawal phase will last at least 6 minutes. Polyp resection will be done during withdrawal in all groups. Time for polypectomy or biopsy will add to the total colonoscopy time. Pathology reports of all polyps will be reviewed and recorded to evaluate adenoma detection rate (ADR, defined as the proportion of subjects with at least one adenoma of any size), the location, the total number of adenomas resected per subject(ARR), and the percentage of subjects with advanced adenomas. The amount of water infused during insertion and withdrawal, the number of position changes and any adverse outcome will be recorded. Cardiopulmonary function will be monitored. Significant oxygen desaturation (\<85% for \>15 seconds) will be recorded. Vagal reaction will be defined as heart rate \<60 beats per minute accompanied by excessive sweating, nausea and/or vomiting.

A Comparison of Air Insufflation, Water Immersion and Water Exchange Colonoscopy in Diagnostic Patients

A Randomized, Controlled Trial Comparing Air Insufflation, Water Immersion and Water Exchange During on Demand Sedation Colonoscopy in Diagnostic Patients

Change in patient position as needed if advancement of the colonoscope fails.

Applied as needed if advancement of the colonoscope fails.

Amount of infused water during insertion and withdrawal.

Bloating felt by patients at completion of examination on a 10 point visual analogue scale.

Bloating felt by patients at discharge measured on a ten point visual analogue scale.

Patients willingness to repeat the examination based on overall satisfaction about procedure. Measured at discharge on a yes/no question.

Significant oxygen desaturation will be recorded when values less than 85% will be maintained for more than 15 seconds.

Vagal reaction is defined as heart rate \<60 beats per minute accompanied by excessive sweating, nausea and/or vomiting.

Pain will be assessed using a visual analogue scale (VAS) with a score 0=absence of pain, 2=simply "discomfort", 10=the worst possible pain. Before the procedure, an endoscopic nurse will explain the VAS scoring system to the patients. The patient will be informed that the request for pain information is not to remind the patient that the examination should be uncomfortable, but to let the colonoscopist be alerted to the need to use maneuvers to minimize discomfort (e.g. loop reduction, removal of colonic content, abdominal compression and/or change in patient position). At regular intervals during colonoscopy (e.g. every 2-3 minutes) patients will be asked about discomfort or pain. The responses will be recorded, and the maximum pain score noted.

Sedation and analgesia will be available on demand. Medication will be offered when VAS score reaches ≥2 (discomfort). Patients can accept or decline the medication. If patients agree to accept the medication, it will be given. Midazolam, no more than 5 mg per patient, will be used. When pain is reported, sedation will be started with midazolam with a single intravenous dose of 2 mg, plus incremental doses of 1 mg if the patient still continues to complain about pain. To avoid bias by the colonoscopist, sedation medication will be administered based on the patients' confirmation that the pain is no longer tolerable, and not at the discretion of the colonoscopist. No other analgesic or sedative medications will be administered. The colon segment in which patients requests sedation will be recorded.

After the procedure and at discharge from the Endoscopy Unit, an assistant nurse blinded to the procedure will ask patients about overall pain using the same VAS when neither the endoscopist nor the assistant nurse who performed the colonoscopy were present. Patients will be asked to quantify the degree of pain experienced and to place a mark over the VAS accordingly.

Cecal intubation will be defined as passage of the tip of the colonoscope beyond the ileocecal valve so that the medial wall of the cecum proximal to the ileocecal valve will be observed. This will be analyzed on an intention- to-treat basis according to group allocation.

Cecal intubation time will be defined as the time for passage of the colonoscope from the rectum to the cecum.

Total procedure time (including time required for polyp resection or biopsy).

Proportion of subjects with at least one adenoma of any size.

Total number of adenomas resected per subject.

Total number of advanced adenomas: diameter ≥10mm, or high grade dysplasia, or with ≥20% villous components.

Presidio Ospedaliero Santa Barbara

Responsabile Servizio Endoscopia Digestiva

Digestive System Diseases

Colonic Polyps

Colonic Neoplasms

Colorectal Neoplasms

Intestinal Neoplasms

Gastrointestinal Neoplasms

Digestive System Neoplasms

Gastrointestinal Diseases

Colonic Diseases

Intestinal Diseases

Standard colonoscopy - no distal colonoscope attachment will be used in this arm

The Olympus transparent cap will be attached to the distal end of colonoscope prior to starting the procedure

The Medivators Endocuff will be attached to the distal end of colonoscope prior to starting the procedure

Olympus transparent cap

Medivators Endocuff

Control

The goal of this study is to compare two FDA approved distal colonoscope attachment devices, in order to identify which device can increase adenoma detection rate the most without increasing procedure time or risk.

Although mortality from colon cancer is decreasing, it remains the second leading cause of cancer related death in the United States. There are multiple factors contributing to this decrease, such as increased awareness, improving screening techniques, etc.

Of the available modalities approved for colon cancer screening in the United States, colonoscopy is considered the gold standard. Colonoscopy has the advantage of being both diagnostic and therapeutic, allowing the removal of pre-cancerous polyps, before the polyps can transform into cancer. Colonic polyps can occur at any location from the rectum to the cecum. Colonoscopy has been shown to be more effective in decreasing incidence of cancer in the left colon but remains limited in the detection of right sided polyps /lesions 2. This difference based on location is thought to be due to several reasons. Typically the right side of the colon is less clean than the left side during colonoscopy, thereby impairing visualization of polyps. This problem has been overcome by incorporating a "split bowel preparation", which has not become standard of care. However, the problem of not being able to visualize polyps behind folds seen in the colon persists despite improvements in the quality of cleansing of the colon. Various endoscopic technologies have been introduced with the goal of assisting with the manipulation of such colonic folds, and thereby reducing chances of missing polyps behind fold. Two such colonoscope assisted devices including the distal transparent cap and the Endocuff endoscopic overtube.

The Endocuff overtube is a small device with flexible arms arranged in 2 rows. Each row has 8 short, soft arms projecting away from the device. These arms are used to peel back the colonic folds without causing physical damage to enable visualization behind colonic folds. The use of Endocuff overtube has shown promising results in terms of cecal intubation rate and time as well as adenoma detection rates 3.

The transparent cap attachment is a clear plastic device that fits at the end of the colonoscope and extends a short distance past the tip of the colonoscope. It aids in the manipulation of folds and in maintaining a suitable distance from the mucosa, with the goal of improving visualization. Although some studies comparing cap fitted colonoscopy to standard (non- attachment) colonoscopies have shown improved adenoma detection 4, others have shown no significant benefit 5.

Although, these devices have been compared with conventional colonoscopies (i.e without any distal attachment), to the investigator's knowledge, there are currently no studies that have compared these two distal colonoscope attachment devices head-to-head, and none has specifically evaluated effects on detection of right sided adenomas. Also, here at UCDavis, these devices are being used specifically in diagnostic colonoscopies for removal of large polyps and the choice of which specific device is used depends on level of comfort of the advanced endoscopist. The endoscopists participating in the investigators' study do not currently use these devices as part of their routine colonoscopies, thus it is important to provide head to head comparison of these devices to help guide management practice.

Therefore, the investigators' goal is to compare the Endocuff overtube assisted, transparent cap fitted, and non-cap fitted (standard) colonoscopy in patients presenting to UC Davis Medical Center for screening colonoscopies.

In addition, 2 of the 3 investigators will employ the water exchange method during for all arms of the trial, while the other investigator will employ the conventional air method of colonoscopy.

Comparison of Colon Adenoma Detection Rate Using Two Distal Colonoscope Attachments

The investigators will compare adenoma detection rate at completion of study across the 3 arms

The investigators will compare proximal adenoma detection rate at completion of study across the 3 arms

The investigators will compare cecal intubation rate at completion of study across the 3 arms

The investigators will compare colonoscopy withdrawal time rate at completion of study across the 3 arms

University of California, Davis

Standard colonoscopy - no distal colonoscope attachment will be used in this arm

Control: No distal colonoscope attachments

The Olympus transparent cap will be attached to the distal end of colonoscope prior to starting the procedure

Olympus transparent cap: distal colonoscope attachment

Olympus Transparent Cap

The Medivators Endocuff will be attached to the distal end of colonoscope prior to starting the procedure

Medivators Endocuff: distal colonoscope attachment

No distal colonoscope attachment will be used in this arm

Control: No distal colonoscope attachments

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy	NCT02880748	Adenoma	Water exchange ... Air insufflatio...	18 Years - 80 Years	Air Force Military Medical University, China
Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Colonoscopy	NCT04464135	Adenoma Colon	acetic acid sta... Water exchange ...	40 Years - 70 Years	Air Force Military Medical University, China
Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy	NCT02880748	Adenoma	Water exchange ... Air insufflatio...	18 Years - 80 Years	Air Force Military Medical University, China
Adenoma Miss Rate With Water Exchange vs Carbon Dioxide Colonoscopy	NCT03832322	Colonic Adenoma Water Exchange ...	Water exchange ... CO2 insufflatio...	20 Years - 75 Years	Evergreen General Hospital, Taiwan
Adenoma Miss Rate With Water Exchange vs Carbon Dioxide Colonoscopy	NCT03832322	Colonic Adenoma Water Exchange ...	Water exchange ... CO2 insufflatio...	20 Years - 75 Years	Evergreen General Hospital, Taiwan
A Comparison of Air Insufflation, Water Immersion and Water Exchange Colonoscopy in Diagnostic Patients	NCT01781650	Pain Colorectal Aden... Colorectal Canc...	Air Insufflatio... Water Immersion... Water Exchange ...	18 Years - 85 Years	Presidio Ospedaliero Santa Barbara
Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Colonoscopy	NCT04464135	Adenoma Colon	acetic acid sta... Water exchange ...	40 Years - 70 Years	Air Force Military Medical University, China
Adenoma Miss Rate With Water Exchange vs Carbon Dioxide Colonoscopy	NCT03832322	Colonic Adenoma Water Exchange ...	Water exchange ... CO2 insufflatio...	20 Years - 75 Years	Evergreen General Hospital, Taiwan
A Comparison of Air Insufflation, Water Immersion and Water Exchange Colonoscopy in Diagnostic Patients	NCT01781650	Pain Colorectal Aden... Colorectal Canc...	Air Insufflatio... Water Immersion... Water Exchange ...	18 Years - 85 Years	Presidio Ospedaliero Santa Barbara
Comparison of Colon Adenoma Detection Rate Using Two Distal Colonoscope Attachments	NCT02665741	Colon Cancer Sc... Colon Polyps Colon Adenomas Water Exchange ...	Olympus transpa... Medivators Endo... Control	50 Years -	University of California, Davis

Spots Global Cancer Trial Database for water exchange colonoscopy