Split-dose bowel preparation for colonoscopy and residual gastric fluid volume: an observational study
Related Experiment Video
Updated: Jun 10, 2026

Gastric Point of Care Ultrasound in Adults: Image Acquisition and Interpretation
Published on: September 22, 2023
Melanie Huffman1, R Zackary Unger, Chandana Thatikonda
1Division of Gastroenterology/Hepatology, Indiana University Hospital, Indianapolis, Indiana, USA.
Background:
Split-dose bowel preparations for colonoscopy are more effective and better tolerated than preparations given entirely the day or evening before the procedure; however, some resistance to split-dose preparation stems from concerns about an increased risk of aspiration with same-day preparation.
Objective:
We sought to evaluate residual gastric volumes in patients after split-dose bowel preparations.
Design:
Prospective measurement of residual gastric volumes in patients undergoing same-day EGD and colonoscopy after split-dose bowel preparations, patients undergoing EGD alone, or patients undergoing EGD and colonoscopy after bowel preparation given entirely the evening before the procedure.
Setting:
Tertiary care hospital-based endoscopy unit.
Patients:
This study involved 712 patients, including 254 in the split-dose bowel preparation group, 411 in the EGD-only group, and 47 in the evening-before-procedure bowel preparation group.
Intervention:
Measurement of residual gastric volume before endoscopic procedures.
Main Outcome Measurements:
Residual gastric volume.
Results:
The mean residual gastric volume in patients receiving split-dose bowel preparation (19.7 mL) was higher than in patients undergoing EGD alone (14.6 mL) but not different from that in patients receiving bowel preparation the evening before the procedure (20.2 mL). Within the split-dose preparation group, there was no association between the interval from last actual fluid ingestion and procedure start time and the residual gastric volume. The range of residual gastric volumes between study arms was similar.
Limitations:
Nonrandomized study. The number of inpatients undergoing split-dose bowel preparation was small.
Conclusion:
These data support the safety of split-dose bowel preparation for outpatients undergoing colonoscopy.
Related Concept Videos
Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy
Sigmoidoscopy
Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus...
Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy
Radionuclide Testing
Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders.
In gastric emptying studies, a meal's liquid and solid...
Lower GI Series: Barium Enema
Procedure Details
The examination begins by inserting a lubricated rectal tube into the patient's rectum to administer a radiopaque barium solution. The barium flow is carefully...
Endoscopic Procedures II: Colonoscopy
Upper GI Series: Barium Swallow
Purpose and Procedure
Patients undergoing this procedure ingest a liquid containing barium sulfate with a chalky...
One-Compartment Open Model for IV Bolus Administration: Estimation of Clearance
In the one-compartment open model for intravenous (IV) bolus administration, clearance is estimated by dividing the elimination rate by the plasma drug concentration. This equation leverages the elimination rate constant and the apparent...