A pilot study using reduced-volume oral sulfate solution as a preparation for colonoscopy among a Japanese population

This pilot study sought to investigate the performance and safety of a reduced-volume oral sulfate solution for use as a bowel-cleansing regimen prior to colonoscopy in a Japanese population. Subjects followed a prescribed split-dose regimen in which the first portion was taken on the evening before colonoscopy and the second portion on the morning of the procedure. To determine the performance of this regimen, the quality of colon cleansing was assessed in each case using a validated four-point scale, and elapsed time to complete the preparation was recorded. Side effects and adverse events were investigated by blood sampling and questionnaire. The successful preparation rate based on the colon-cleansing score was 97 % (30/31). Mean elapsed time to complete the preparation on the day of colonoscopy was 71 min. Serum levels of indirect bilirubin were significantly increased to abnormal levels following the preparation, although these changes were only transient. Preparation-related symptoms of nausea and vomiting were presented in only one case. This pilot study showed the oral sulfate solution-based bowel preparation to be safe, easy, and quick to use for Japanese patients. A larger study is necessary to statistically verify these results.