The Impact of Image-Assisted Colonoscope on Patient Experience, Physician Workload, and Examination Quality (LOOP-p1)

Colonoscopy is the cornerstone for colorectal cancer screening, diagnosis, and post-treatment surveillance. Procedural quality is influenced by patient anatomy, particularly variations in colonic configuration such as sigmoid redundancy, looping, and low-lying transverse colon. These features prolong insertion time, increase patient discomfort, and elevate physician workload.

Evidence suggests that prior CT imaging can provide objective and individualized information on colonic anatomy-such as redundancy, angulation, and tortuosity-potentially predicting procedural difficulty. However, existing studies are mainly retrospective or descriptive, lacking prospective randomized evidence on clinical utility.

This single-blind, randomized controlled trial evaluates whether image-assisted colonoscope insertion, based on pre-existing abdominal/pelvic CT scans, can improve cecal intubation time, enhance patient experience, reduce operator workload, and improve overall examination quality compared with standard colonoscopy.

Study Overview

• Status: Recruiting
• Conditions: Colorectal Cancer Screening; Colonic Polyps/Colonoscopy/Colorectal Neoplasms; Difficult Colonoscopy; Colonoscopy-Related Discomfort
• Intervention / Treatment: Other: CT-Based Image-Assisted Colonoscope Insertion

Detailed Description

Colonoscopy performance varies widely among patients, with anatomical factors being major contributors to insertion difficulty. Prior CT colonography studies demonstrate high interindividual variability in colon length, flexures, and tortuosity, and up to 73% of patients experience looping during colonoscopy. Fluoroscopy-guided maneuvers have been shown to resolve looping in >95% of cases, highlighting the potential value of anatomical prediction.

This study investigates the feasibility and effectiveness of using information extracted from a patient's previous abdominal/pelvic CT scan (≤5 years) to guide insertion strategy during colonoscopy. Image-assisted guidance may help endoscopists anticipate looping patterns, identify redundant segments, and plan insertion maneuvers more effectively.

A total of 140 participants will be randomized 1:1 into an image-assisted group or standard group. The primary endpoint is cecal intubation time. Secondary endpoints include patient-reported pain (VAS), willingness for future colonoscopy, operator workload (NASA-TLX), looping events, total procedure time, and polyp detection rate. Consistency between CT-based predictions and actual procedural findings will also be assessed.

This trial will provide foundational evidence for individualized, anatomy-informed colonoscopy strategies and support future large-scale studies or AI-assisted implementation.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kun He, MD; Phone Number: 15901623698; Email: hk6290418@163.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100730
      • Recruiting
      • Peking Union Medical College Hospital
      • Contact: Dong Wu, M.D.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 18-80 years, or expected natural survival >3 years
• Undergoing colonoscopy at Peking Union Medical College Hospital
• Presence of an abdominal/pelvic CT scan performed within ≤5 years and no - - - major abdominal surgery afterward
• Patient or legal guardian able to understand the study and provide written consent

Exclusion Criteria:

• No available CT or CT quality insufficient for anatomical evaluation
• Prior colonic surgery affecting anatomy (e.g., right hemicolectomy, transverse colectomy)
• Severe cardiopulmonary dysfunction or coagulopathy
• Pregnancy
• Refusal to participate or inability to complete questionnaires
• Patient or guardian unable to understand study requirements

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Image-Assisted Colonoscopy; Participants undergo colonoscopy with pre-procedural review of their existing abdominal/pelvic CT scan (≤5 years). Endoscopists complete a standardized imaging assessment form including predicted redundancy, looping type, tortuosity, and segmental laxity. No additional imaging is performed.	Other: CT-Based Image-Assisted Colonoscope Insertion; This intervention uses pre-existing abdominal or pelvic CT imaging (within 5 years, without major abdominal surgery) to assess individual colonic morphology prior to colonoscopy. Key CT-derived features include colonic redundancy, looping patterns, fixation points, and segmental angulation. Based on these findings, the endoscopist receives a structured, standardized briefing before colonoscope insertion, including predicted difficult segments and recommended insertion strategies. No additional imaging, radiation, or invasive procedures are used. The intervention aims to improve insertion efficiency, reduce patient discomfort, and lower operator workload compared with standard colonoscopy without image guidance.
No Intervention: Standard Colonoscopy; Participants undergo colonoscopy per routine clinical practice without CT-based anticipatory guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cecal Incubation Time (minutes)	Time from scope insertion to visualization of the cecum	Periprocedural (during colonoscopy procedure)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Score (VAS 0-10)	Patient-reported pain assessed using a Visual Analog Scale (VAS) ranging from 0 (no pain) to 10 (worst pain imaginable).	Immediately after colonoscopy (periprocedural)
Physician Workload	NASA-TLX Score (0-100)	Immediately after colonoscopy
Willingness for Future Colonoscopy (5-point Likert scale)	Patient willingness to undergo repeat colonoscopy assessed using a 5-point Likert scale.	Immediately after colonoscopy
Polyp Detection Rate (PDR) (%)	Proportion of colonoscopies in which at least one polyp is detected.	During colonoscopy procedure
Number of Looping Attempts	Total number of looping events requiring corrective maneuvers during colonoscope insertion.	During colonoscopy procedure

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Agreement Between CT-Based Prediction and Procedural Findings	Agreement between pre-procedural CT-based anatomical predictions and actual procedural findings, including predicted looping type, colonic redundancy, and insertion difficulty grade, assessed using Cohen's kappa statistics.	During colonoscopy procedure

Collaborators and Investigators

• Sponsor: DONG WU

Study record dates

Study Major Dates

• Study Start (Actual): December 9, 2025
• Primary Completion (Actual): January 30, 2026
• Study Completion (Estimated): May 28, 2026

Study Registration Dates

• First Submitted: December 9, 2025
• First Submitted That Met QC Criteria: April 14, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: April 14, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Colonoscopy; Looping; Cecal Intubation Time; Image-Assisted Colonoscopy; Personalized Colonoscopy
• Additional Relevant MeSH Terms: Pathological Conditions, Anatomical; Polyps; Intestinal Polyps; Pathological Conditions, Signs and Symptoms; Colonic Polyps
• Other Study ID Numbers: P20251209-1001; 2024YFA0918504 (Other Identifier: National Key Research and Development Program of China)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The individual participant data (IPD) will not be shared. Only aggregated results will be published.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No