A Prospective Endoscopic Blind Trial Comparing Precolonoscopy Bowel Cleansing Methods

Min, Young Il; Kim, Hae Ryun; Jung, Hwoon Yong; Kim, Suk Gyun; Jung, Sung Ae; Hong, Weon Seon; Shim, Ki Nam; Park, Eui Ryun; Yang, Suk Kyun; Cho, Moon Kyung; Lee, Hun Kyung; Kim, Seung Yong

Abstract

BACKGROUND AND AIMS
Although some authors have suggested that sodium phosphate (NaP) is more effective than polyethylene glycol (PEG) in bowel cleansing, there has been no crossover study proving the superiority of NaP over PEG in bowel cleansing and patients' compliance. The aim of this study was to compare the two solutions for colonoscopy, PEG and NaP, through crossover design with regard to patients' compliance, cleansing ability and side effects. METHODS: Thirty patients underwent two separate colonoscopies for colonic polyp(s) with PEG and NaP, respectively. Before and after bowel preparation, blood pressure, body weight, and serum biochemical parameters were measured in all patients. In addition, a detailed questionnaire was used to assess side effects and the patients' preference. The presence of bubbles, types of residual stool, and overall quality of colon cleansing were assessed by one endoscopist blinded to the type of preparation used. In each colonoscopy, two biopsy specimens were taken at rectum. RESULTS: In the NaP group, but not in the PEG group, there were significant changes in several biochemical parameters including sodium ( +3.0 +/- 3.0 mEq/L), potassium ( -0.3 +/- 0.3mEq/L), calcium ( -0.5 +/- 0.5 mg/dL), phosphorus ( +3.9 +/- 2.2 mg/dL) and osmolarity ( +10.1 +/- 9.3 mOsm/kg) after bowel preparation. In addition, the degree of body weight change was greater with NaP ( -2.2 +/- 2.3 kg) than with PEG ( -1.2 +/- 2.0 kg) (p=0.06) and the formation of bubbles that disturb luminal observation was more frequently found in the NaP group (p<0.01). There was no difference, however, in the type of residual stool and the overall quality of bowel preparation between the two groups and no significant mucosal change was noted after bowel preparation in both groups. Moreover, PEG was found to be more difficult to take than NaP (p<0.05) and among the 30 patients, 26 (87%) preferred NaP, while only two favored PEG (p<0.01). CONCLUSIONS: We conclude that NaP can replace PEG at least in patients with good general condition. Further studies to decrease the incidence of bubbles and to establish subgroups suitable for NaP are needed.