[Comparison between conventional 4 L polyethylene glycol and combination of 2 L polyethylene glycol and sodium phosphate solution as colonoscopy preparation].

Background/aims: Effective bowel preparation is essential for accurate diagnosis of colon disease. We investigated efficacy and safety of 2 L polyethylene glycol (PEG) solution with 90 mL sodium phosphate (NaP) solution compared with 4 L PEG method.

Methods: Between August 2009 and April 2010, 526 patients were enrolled who visited Seoul National University Bundang Hospital for colonoscopy. We allocated 249 patients to PEG 4 L group and 277 patients to PEG 2 L with NaP 90 mL group. Detailed questionnaires were performed to investigate compliance, satisfaction and preference of each method. Bowel preparation quality and segmental quality were evaluated. Success was defined as cecal intubation time less than 20 minutes without any help of supervisors.

Results: Both groups revealed almost the same baseline characteristics except the experience of operation. PEG 4 L group's compliance was lower than PEG 2 L with NaP 90 mL group. Success rate and cecal intubation time was not different between two groups. Overall bowel preparation quality of PEG 2 L with NaP 90 mL group was better than PEG 4 L group. Segmental bowel preparation quality of PEG 2 L with NaP 90 mL group was also better than PEG 4 L group in all segments, especially right side colon. Occurrence of hyperphosphatemia was higher in PEG 2 L with NaP 90 mL group than PEG 4 L group. However, significant adverse event was not reported.

Conclusions: PEG 2 L with NaP 90 mL method seems to be more effective bowel preparation than PEG 4 L method.