Effect of Miralax NPO Time on Residual Gastric Volumes and Bowel Preparation

May 26, 2026 updated by: Stephanie Jiaying Pan, Stanford University
The goal of this clinical trial is to assess differences in residual gastric volumes after stopping Miralax ingestion at different time points (1-4 hours) prior to anesthesia induction.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Not Applicable

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

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients undergoing both EGD and colonoscopy
  • Use of Miralax for cleanout
  • Patients <19 years old

Exclusion Criteria:

  • Patients with a history of delayed gastric emptying (eg diabetic, GLP-1 intake)
  • Patients with a history of gastric sleeve surgery
  • Use of Golytely for cleanout
  • Emergent EGD/colonoscopies
  • EGD/colonoscopies for foreign body removal and/or decompression
  • Known neurologic compromise
  • Presence of pre-existing ostomy, short bowel syndrome, gastric retention, intestinal obstruction, ileus, bowel perforation, toxic colitis, toxic megacolon, swallowing difficulties
  • Pre-existing electrolyte derangements
  • Allergy to Miralax

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: 4hr NPO
Miralax will be stopped 4 hours prior anesthesia induction
Behavioral: Stopping Miralax ingestion 4 hours prior to anesthesia induction
Stopping Miralax ingestion 4 hours prior to anesthesia induction
Active Comparator: 3hr NPO
Miralax will be stopped 3 hours prior anesthesia induction
Behavioral: Stopping Miralax ingestion 3 hours prior to anesthesia induction
Stopping Miralax ingestion 3 hours prior to anesthesia induction
Active Comparator: 2hr NPO
Miralax will be stopped 2 hours prior anesthesia induction
Behavioral: Stopping Miralax ingestion 2 hours prior to anesthesia induction
Stopping Miralax ingestion 2 hours prior to anesthesia induction
Active Comparator: 1hr NPO
Miralax will be stopped 1 hour prior anesthesia induction
Behavioral: Stopping Miralax ingestion 1 hour prior to anesthesia induction
Stopping Miralax ingestion 1 hour prior to anesthesia induction

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Residual gastric volume as measured by EGD
Time Frame: To be performed at the start of the EGD immediately after anesthesia induction.
To be performed at the start of the EGD immediately after anesthesia induction.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Preoperative gastric POCUS volume assessment
Time Frame: Performed prior to anesthesia induction
Performed prior to anesthesia induction
Effectiveness of colonoscopy cleanout
Time Frame: Performed during the colonoscopy portion following upper GI endoscopy (EGD)
The effectiveness of colonoscopy cleanout will be assessed by the Boston Bowel Preparation Scale (BBPS).
Performed during the colonoscopy portion following upper GI endoscopy (EGD)
Incidence of aspiration on induction and perioperative aspiration
Time Frame: On anesthesia induction
On anesthesia induction

Collaborators and Investigators

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

Sponsor

Stanford University

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 (Estimated)

July 1, 2026

Primary Completion (Estimated)

June 1, 2028

Study Completion (Estimated)

June 1, 2028

Study Registration Dates

First Submitted

May 17, 2026

First Submitted That Met QC Criteria

May 26, 2026

First Posted (Actual)

June 1, 2026

Study Record Updates

Last Update Posted (Actual)

June 1, 2026

Last Update Submitted That Met QC Criteria

May 26, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 86683

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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