Time Interval After Gastric Emptying and Quality of Bowel Cleansing

December 12, 2025 updated by: Nanjing First Hospital, Nanjing Medical University

Correlation Between Time Interval After Gastric Emptying With Ultrasound Assessment and Quality of Bowel Cleansing in Patients Undergoing Painless Colonoscopy: a Randomized, Prospective, Controlled Trial

The goal of this [clinical trial] is to [explore the balance time point between the waiting time for intestinal preparation after gastric emptying and quality of bowel preparation.] in [patients with painless colonoscopy]. The main question[s] it aims to answer are:

[whether the gastric is empty or not 2 hours after finishing drinking 1.5 L of MgSO4 solution within 2 hours] [whether the quality of patients' bowel preparation is superior in a time period of 2-4 hours after finishing drinking 1.5 L of MgSO4 solution] Participants will [ be asked finishing the last dose of 1.5 L MgSO4 solution within 2 hours and received ultrasound gastric assessment immediately 2 or 4 hours after finishing drinking MgSO4 solution in a 15 minutes time interval until the gastric is empty. As soon as the gastric is empty, patients receive painless colonoscopy within 2 hours or 2-4 hours.

Researchers will compare [patients receiving painless colonoscopy within 2 hours or 2-4 hours after finishing drinking 1.5 L of MgSO4 solution] to see if [the quality of patients' bowel preparation is superior in a time period of within 2 hours].

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

All subjects ate a light diet the day before the examination and fasted after 19:00 on the night before examination. A segmented intestinal cleansing regimen of 3L MgSO4 was adopted: 1.5L was taken one night before the examination; On the day of the examination, the second dose of 1.5L was taken and finished within 2 hours. The medication method was guided by professional nursing staff. All subjects were instructed to take appropriate activities during the administration of intestinal cleanser to promote excretion. Patients were divided into two groups (group A and group B) using random number table method. Patients in group A received gastric ultrasound examination every 15 minutes 2 hours immediately after taking the last dose of MgSO4 solution. During this period, if the gastric ultrasound showed that the patient had an "empty stomach", and painless colonoscopy was performed within 2 hours while the gastric is empty. If the gastric ultrasound still showed "full stomach" at 4h, the patient was abandoned, but gastric ultrasound assessment continued until the stomach was empty. The patients in group B received gastric ultrasound examination every 15min 4h immediately after taking the last dose of MgSO4 solution on the examination day, and colonoscopy was to completed within 4-6h after taking the MgSO4 solution if the gastric ultrasound showed that the patient had an "empty stomach". If the gastric ultrasound still shows "full stomach" at 6h, it is eliminated, but continuing to perform gastric ultrasound every 15min until the " stomach was empty ". All patients received general anesthesia by the same senior anesthesiologist using propofol 2 mg/kg and remifentanil 0.2 ug/kg. The BIS value of anesthesia depth was controlled in the range of 40-60, and propofol and remifentanil were added as needed. The same chief gastroenterologist performed the colonoscopy and evaluated the quality of intestinal cleaning.

Study Type

Interventional

Enrollment (Actual)

148

Phase

  • 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

  • China
    • Jiangsu
      • Nanjing, Jiangsu, China, 210006
        • Nanjing First Hospital

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

1.Patients who receiving elective colonoscopy under general anesthesia

Exclusion Criteria:

  1. Patients with severe heart and lung diseases who cannot tolerate anesthesia or colonoscopy
  2. chronic constipation
  3. history of gastric or intestinal surgery
  4. diabetes, Parkinson's disease, stroke,

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: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: colonoscopy within 2-4 h
Patients received ultrasound gastric assessment every 15 minutes 2 hours immediately after taking the last dose of MgSO4 solution. During this period, if the gastric ultrasound assessment showed that the patient had an "empty stomach", and painless colonoscopy was performed within 2 hours while the gastric is empty.
Other: after ultrasound gastric assessment to ensure gastric empty, painless colonoscopy was performed within 2 hours
Patients received gastric ultrasound examination every 15 minutes 2 or 4 hours immediately after taking the last dose of MgSO4 solution in group A or B respectively.
Other Names:
  • Ultrasound gastric assessment
No Intervention: colonoscopy within 4-6 h
The patients received ultrasound gastric assessment every 15min 4h immediately after taking the last dose of MgSO4 solution on the examination day, and colonoscopy was to completed within 4-6h after taking the MgSO4 solution if the gastric ultrasound assessment showed that the patient had an "empty stomach".

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
full stomach rate after finishing MgSO4 solution under different waiting time
Time Frame: 2 or 4 hours after finishing taking MgSO4 solution
recording full stomach rate using gastric ultrasound
2 or 4 hours after finishing taking MgSO4 solution
Boston bowel preparation quality scale
Time Frame: five minutes after finishing colonoscopy examination
Using Boston bowel preparation quality scale: 3 score, the intestinal cleaning range is more than 90%, no fecal residue, clear vision, or only some clear liquid exists; 2 score, The intestinal cleaning range was 75% to 90%, only a small amount of intestinal residue or fecal water remained, which had no effect on the examination and observation; 1 score,fecal residue or fecal water exists in more intestinal segments, and can continue to enter the lens after rinsing with water; 0 score: There are more fecal residues in the intestinal cavity, and it is impossible to continue the examination. According to the above scoring criteria, the intestinal cleanliness of the left colon, transverse colon and right colon were scored respectively. The total score ≥6 was considered to be good intestinal preparation. The total score < 6 points was considered that the intestinal preparation was poor.
five minutes after finishing colonoscopy examination

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The rate of ileum intubation while performing colonoscopy
Time Frame: while performing colonoscopy
recording rate of ileum intubation
while performing colonoscopy
the detection rate of polyp and adenoma while performing colonoscopy
Time Frame: while performing colonoscopy
recording the detection rate of polyp and adenoma
while performing colonoscopy

Collaborators and Investigators

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

Sponsor

Nanjing First Hospital, Nanjing Medical University

Investigators

  • Study Chair: Gu JianPing, Nanjing First Hospital, Nanjing Medical 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

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)

November 1, 2023

Primary Completion (Actual)

June 30, 2024

Study Completion (Actual)

December 30, 2024

Study Registration Dates

First Submitted

September 21, 2023

First Submitted That Met QC Criteria

October 26, 2023

First Posted (Actual)

November 1, 2023

Study Record Updates

Last Update Posted (Actual)

December 19, 2025

Last Update Submitted That Met QC Criteria

December 12, 2025

Last Verified

March 1, 2024

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • KY20230428-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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