Clinical Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2005; 11(47): 7486-7493
Published online Dec 21, 2005. doi: 10.3748/wjg.v11.i47.7486
Prospective randomized comparison of oral sodium phosphate and polyethylene glycol lavage for colonoscopy preparation
Kai-Lin Hwang, William Tzu-Liang Chen, Koung-Hong Hsiao, Hong-Chang Chen, Ting-Ming Huang, Chien-Ming Chiu, Ger-Haur Hsu
Kai-Lin Hwang, Department of Public Health, Chung-Shan Medical University, Taichung 402, Taiwan; Center for Clinical Trials, ChangHua Christian Hospital, Changhua 500, Taiwan, China
William Tzu-Liang Chen, Koung-Hong Hsiao, Hong-Chang Chen, Ting-Ming Huang, Chien-Ming Chiu, Ger-Haur Hsu, Division of Colorectal Surgery at ChangHua Christian Hospital, Changhua 500, Taiwan, China This study was conducted at the Division of Colorectal Surgery at ChangHua Christian Hospital, Changhua 500, Taiwan, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. William Tzu-Liang Chen, Division of Colorectal Surgery, ChangHua Christian Hospital, 135 Nanhsiao Street, Changhua, 500, Taiwan, China. 37599@cch.org.tw
Telephone: +886-4-7238595 Fax: +886-4-7227945
Received: April 7, 2005
Revised: July 2, 2005
Accepted: July 8, 2005
Published online: December 21, 2005
Abstract

AIM: To compare the effectiveness, patient acceptability, and physical tolerability of two oral lavage solutions prior to colonoscopy in a Taiwanese population.

METHODS: Eighty consecutive patients were randomized to receive either standard 4 L of polyethylene glycol (PEG) or 90 mL of sodium phosphate (NaP) in a split regimen of two 45 mL doses separated by 12 h, prior to colonoscopic evaluation. The primary endpoint was the percent of subjects who had completed the preparation. Secondary endpoints included colonic cleansing evaluated with an overall assessment and segmental evaluation, the tolerance and acceptability assessed by a self-administered structured questionnaire, and a safety profile such as any unexpected adverse events, electrolyte tests, physical exams, vital signs, and body weights.

RESULTS: A significantly higher completion rate was found in the NaP group compared to the PEG group (84.2% vs 27.5%, P<0.001). The amount of fluid suctioned was significantly less in patients taking NaP vs PEG (50.13±54.8 cc vs 121.13±115.4 cc, P<0.001), even after controlling for completion of the oral solution (P = 0.031). The two groups showed a comparable overall assessment of bowel preparation with a rate of “good” or “excellent” in 78.9% of patients in the NaP group and 82.5% in PEG group (P = 0.778). Patients taking NaP tended to have significantly better colonic segmental cleansing relative to stool amount observed in the descending (94.7% vs 70%, P = 0.007) and transverse (94.6% vs 74.4%, P = 0.025) colon. Slightly more patients graded the taste of NaP as “good” or “very good” compared to the PEG patients (32.5% vs 12.5%; P = 0.059). Patients’ willingness to take the same preparation in the future was 68.4% in the NaP compared to 75% in the PEG group (P = 0.617). There was a significant increase in serum sodium and a significant decrease in phosphate and chloride levels in NaP group on the day following the colonoscopy without any clinical sequelae. Prolonged (>24 h) hemodynamic changes were also observed in 20-35% subjects of either group.

CONCLUSION: Both bowel cleansing agents proved to be similar in safety and effectiveness, while NaP appeared to be more cost-effective. After identifying and excluding patients with potential risk factors, sodium phosphate should become an alternative preparation for patients undergoing elective colonoscopy in the Taiwanese population.

Keywords: Colonoscopy; Bowel preparation; Sodium phosphate; Polyethylene glycol