Two liters of polyethylene glycol-electrolyte lavage solution versus sodium phosphate as bowel cleansing regimen for colonoscopy: a prospective randomized controlled trial

BACKGROUND AND STUDY AIMS: As a bowel cleansing agent for colonoscopy, sodium phosphate (NaP) has been reported to have equal effectiveness and better patient tolerance in comparison with 4 l polyethylene glycol-electrolyte lavage (PEG-EL) solution. Poor patient tolerance is frequently associated with a large amount of fluid consumed, and better patient tolerance might therefore be expected if the volume of PEG-EL solution could be reduced. This study aimed to compare 2 l PEG-EL solution with NaP in relation to patients' tolerance and its effectiveness as a bowel cleansing agent. PATIENTS AND METHODS: Two hundred consecutive patients admitted to the day-procedure ward for elective colonoscopy were prospectively randomized to receive either a 2-l PEG-EL solution or a 90-ml oral NaP regimen. Patients with a history of congestive heart failure, impaired renal function (creatinine > 1.5 mg/dl), or previous colectomy were excluded from the study. The patients completed a questionnaire to assess their tolerance of bowel preparation before the colonoscopy. Endoscopists, who were blinded to the type of regimen that had been used, scored the adequacy of bowel preparation from the rectum to cecum using a defined endoscopic score. RESULTS: Two hundred patients were included in this randomized trial. Nine patients were excluded, due to either an incomplete questionnaire (two in the PEG-EL group, one in the NaP group) or inability to complete the bowel preparation regimen (four in the PEG-EL group and two in the NaP group). The demographic data were comparable in the two groups. There were no differences between the two groups with regard to willingness to repeat the regimen, ease of consumption, acceptability of the bowel preparation regimen, or the endoscopists' satisfaction with the quality of bowel preparation. The NaP group had a better mean endoscopic score at the cecum compared with the PEG-EL group (1.47 +/- 1.15 vs. 1.05 +/- 0.76; P = 0.007). CONCLUSIONS: The effectiveness and patient tolerance of the 2-l PEG-EL solution is comparable with that of oral NaP. The 2-l PEG-EL solution is therefore an effective alternative as a bowel-cleansing agent for colonoscopy.