Source: DGNews  |  Posted 3 years ago

By Bruce Sylvester

SAN DIEGO -- May 20, 2008 -- Length of time between completion of bowel preparation and initiation of a colonoscopy is more important than the time of day when the colonoscopy is performed, researchers reported here at Digestive Diseases Week 2008 (DDW).

"In terms of quality of bowel preparation, there was a significant association between the length of interval between last bowel prep dosing and the start of the colonoscopy," said investigator and presenter Ali Siddiqui, MD, Assistant Professor of Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.

Previous research suggested that the time of day of a colonoscopy affects the quality of the bowel preparation, with morning examinations being best. Dr. Siddiqui's findings contradict previous findings. "We saw no such significant association," said Dr. Siddiqui at a press briefing on May 19.

In their study, Dr. Siddiqui and colleagues gathered data prospectively on 378 consecutive outpatients (95.7% male, mean age 62.2 years) undergoing colonoscopies over a 3-month period at a VA Medical Center.

Patients' medical histories, demographics, compliance with bowel preparation and dietary restrictions, and timing since the last dose of the bowel preparation were noted immediately prior to the colonoscopy.

Polyethylene glycol (PEG) electrolyte-based solution was used by 97.3% of patients and oral sodium phosphate was used by 2.7% of patients.

The researchers excluded patients with a right hemicolectomy.

Senior staff endoscopists and endoscopy nurses independently graded the quality of the bowel preparation for the right colon. They used a 5-point scale (0 = excellent to 4 = inadequate) and standard photographic grading procedures. Endoscopists also noted the presence or absence of succus in the right colon.

Results showed that patients whose preparations were "excellent/good" had a significantly shorter interval between the last bowel preparation dosing and the start of colonoscopy than did patients whose preparations scored "fair/poor/inadequate" (P = .013).

The researchers reported no significant difference in bowel preparation quality between morning and afternoon colonoscopies.

They also found no significant relationship between the presence of succus and the interval from the last dose of bowel preparation agent to the start of colonoscopy, or between bowel preparation quality and the time elapsed between the last solid meal and the start of the colonoscopy.

The authors concluded, "For bowel preparation quality, the duration of the interval between the completion of the bowel preparation and the start of the colonoscopy appears to be more important than the time of day when colonoscopy is performed. Bowel preparation quality varies inversely with the duration of the interval between the last dose of the bowel preparation agent and the start of the colonoscopy."

[Presentation title: Duration of the Interval Between Completion of the Bowel Preparation and Start of the Colonoscopy as a Better Predictor of Bowel Preparation Quality Than Colonoscopy Start Time Alone. Abstract 237]