Comparison of the Left-Lateral Horizontal and Supine Positions for Colonoscopy Intervention: A Randomized Controlled Study

April 4, 2026 updated by: Celal Bayar University

Objective: One of the most common technical difficulties during colonoscopy is passing through the fold of the sigmoid colon. Colonoscopy is commonly performed by endoscopists with the patient in the left lateral position. When the procedure is initiated in the left lateral position, insufflation of the bowel may result in a sharper angulation of the sigmoid colon, making advancement of the colonoscope more difficult. This study aimed to compare colonoscopic procedures initiated in the left lateral position and the supine position.

Materials and Methods: Colonoscopy was performed on 198 participants who had an indication for colonoscopy at the General Surgery clinic and met the study inclusion criteria. All procedures were conducted by the same endoscopist (Dr. Semra Tutcu Şahin) in the Endoscopy Unit during working hours. Participants were randomly assigned to two groups:

Group 1: Participants whose starting position for colonoscopy was supine (n=97) Group 2: Participants whose starting position for colonoscopy was left lateral (n=101)

During colonoscopy, participants' demographic data, vital signs, and the time required for the endoscopist to reach the cecum were recorded. At the end of the procedure, participants completed a pain scale, and the endoscopist completed an observation scale. The data were entered into the SPSS program and analyzed.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Objective: One of the most common technical difficulties during colonoscopy is passing through the fold of the sigmoid colon. Colonoscopy is commonly performed by endoscopists with the patient in the left lateral position. When the procedure is initiated in the left lateral position, insufflation of the bowel may result in a sharper angulation of the sigmoid colon, making advancement of the colonoscope more difficult. This study aimed to compare colonoscopic procedures initiated in the left lateral position and the supine position.

Materials and Methods: Colonoscopy was performed on 198 participants who had an indication for colonoscopy at the General Surgery clinic and met the study inclusion criteria. All procedures were conducted by the same endoscopist (Dr. Semra Tutcu Şahin) in the Endoscopy Unit during working hours. Participants were randomly assigned to two groups:

Group 1: Participants whose starting position for colonoscopy was supine (n=97) Group 2: Participants whose starting position for colonoscopy was left lateral (n=101)

During colonoscopy, participants' demographic data, vital signs, and the time required for the endoscopist to reach the cecum were recorded. At the end of the procedure, participants completed a pain scale, and the endoscopist completed an observation scale. The data were entered into the SPSS program and analyzed.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
198

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Female and male patients over 18 years of age who have been medically indicated for colonoscopy and have signed the voluntary consent form.

Exclusion Criteria:

  • Patients under 18 years of age
  • Patients who do not give informed consent
  • Pregnant women
  • Patients requesting sedation
  • Patients with an indication for emergency colonoscopy
  • Patients with a history of colon resection
  • Major psychiatric disorders

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Supine position (SP)
The first group consisted of patients assigned to the supine position (SP) as the initial position for colonoscopy
Procedure: Colonoscopy after bowel cleansing
Colonoscopy after bowel cleansing
Device: Colonoscopy after bowel cleansing
COLONOSCOPY WITH LEFT LATERAL AND SUPINE POSITION
Other: Lateral Left Horizontal Position (LLP)
The second group consisted of patients assigned to the left lateral horizontal position (LLP) as the initial position for colonoscopy
Procedure: Colonoscopy after bowel cleansing
Colonoscopy after bowel cleansing
Device: Colonoscopy after bowel cleansing
COLONOSCOPY WITH LEFT LATERAL AND SUPINE POSITION

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Cecal intubation time
Time Frame: During the colonoscopy procedure
Time (in seconds) from insertion of the colonoscope at the anal verge to successful cecal intubation, defined by visualization of the appendiceal orifice and ileocecal valve, recorded by the endoscopist.
During the colonoscopy procedure

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Pain score during colonoscopy
Time Frame: Immediately after colonoscopy
Pain intensity assessed immediately after the procedure using a 10-point Visual Analog Scale (VASP), where 0 indicates no pain and 10 indicates worst imaginable pain.
Immediately after colonoscopy
Endoscopist-rated procedure difficulty
Time Frame: Immediately after colonoscopy
Procedure difficulty assessed immediately after colonoscopy using a 4-point Likert scale (1 = very easy, 2 = easy, 3 = difficult, 4 = very difficult), as rated by the endoscopist.
Immediately after colonoscopy
Changes in vital signs during colonoscopy
Time Frame: During the colonoscopy procedure
Heart rate (beats per minute) measured at baseline and at 5-minute intervals during the procedure. The maximum change from baseline will be recorded.
During the colonoscopy procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Celal Bayar University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • McKechnie T, Heimann L, Kazi T, Jessani G, Lee Y, Sne N, et al. Starting position during colonoscopy: a systematic review and meta-analysis of randomized controlled trials. Tech Coloproctol [Internet]. 2024;28.
  • Watanabe J. Comparison of left versus right lateral starting position on colonoscopy: A systematic review and meta-analysis of randomized controlled trials. Ann Gastroenterol. 2021;34:699-704.
  • Watanabe J, Park D, Kakehi E, Inoue K, Ishikawa S, Kataoka Y. Efficacy and safety of the starting position during colonoscopy: a systematic review and meta-analysis. Endosc Int Open. 2020;08:848-60.
  • 1. Li N, Lu B, Luo C, Cai J, Lu M, Zhang Y, et al. Incidence, mortality, survival, risk factor and screening of colorectal cancer: A comparison among China, Europe, and northern America. Cancer Lett. 2021;522:255-68.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 15, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 6, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 4, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 8, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CelalBayarU

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Anonymized study results

IPD Sharing Time Frame

Beginning 1 month after publication with no end date

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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