Comparison of Bowel Cleansing Efficacy Between Same-day Dose Versus Split Dose
Condition: Unrecognized Condition
Study type: Interventional
Phase: Phase 3

Summary: 
      Split dose bowel cleansing is recommended method for colonoscopy. For afternoon colonoscopy,
      same-day dose of bowel cleansing is alternative option. Recently, same-day bowel cleansing
      for morning colonoscopy was validated. To date, there was no study which compared the bowel
      cleansing efficacy between same-day dose and split dose regardless of colonoscopy time. The
      aim of current study is to compare the bowel cleansing efficacy, adverse events, and
      patient's tolerability between the two group.

      Subjects who underwent colonoscopy for various reasons were included. After agreeing to
      participate in the study, study participants were randomly assigned to split dose or same day
      dose group. Bowel cleansing is done using polyethylene glycol (PEG). All colonoscopy was done
      between 10 AM to 6 PM. Study participants were instructed to ingest 500ml PEG every 15
      minutes. Subjects who were assigned to split dose group ingested 2L PEG from 9PM 1 day before
      colonoscopy. Remaining 2L PEG was ingested 3-5 hours before colonoscopy. In the same-day dose
      group, bowel cleansing was started from 5AM for subjects who were scheduled to receive
      colonoscopy in the morning. Afternoon colonoscopy group in the same-day dose group ingested
      2L PEG from 5AM. Remaining 2L PEG was finished 3-5 hours before colonoscopy.

      Bowel cleansing efficacy was assessed using Boston bowel preparation scale. Vital signs and
      laboratory tests were checked before colonoscopy. Study participants completed questionnaire
      which contained patient's satisfaction, tolerability, and adverse event during bowel
      cleansing. Bowel cleansing efficacy, patient's tolerability, and safety profile were compared
      between the two groups. Successful bowel cleansing was estimated 85% for split dose group.

      The investigators set 10% for inferior margin. Considering 10% drop out, a total of 352
      subjects will be recruited.
    

Detailed description: 
      Randomization and blinding:

      Randomization will be done using computer generated randomization list. A specialized nurse
      will explain the method of bowel cleansing. Investigators (endoscopists) are blinded to bowel
      cleansing method.

      Endpoint:

      Primary end point is successful bowel cleansing rated by Boston bowel preparation (BBPS)
      scale. Successful bowel cleansing is defined as all segment is 2 or 3 points. Endoscopists
      will assess BBPS when colonoscopy withdrawal.

      Secondary end point was patient's tolerability and safety profile including adverse events.
      Patient's satisfaction to the different bowel cleansing method and adverse events (nausea,
      vomiting, dizziness, fatigue) will be investigated by questionnaire before colonoscopy. Blood
      test will be done before colonoscopy.

      Statistical analysis:

      Bowel cleansing success, patient's tolerability and safety profile will be compared between
      the two groups. Student t test for continuous variables and the chi-square test or Fisher
      exact test for categorical variables.

      Sample size:

      This study is non-inferioty study. Assuming bowel cleansing success rate 85% in the
      split-dose group, the significant difference between the two groups were hypothesized at 10%.
      Considering 80% power and 10% drop rate, a total of 352 participants is needed.
    

Intervention name(s): Polyethylene Glycol (PEG)
Intervention type(s): Drug
Intervention description(s): Different method for bowel cleansing using same bowel cleanser. Same-day dose group : 4L PEG will be ingested on the day of colonoscopy Spli-dose group : 2L PEG will be ingested 1 day before colonoscopy, remaining 2L PEG will be ingested on the day of colonoscopy
Other intervention name(s): colyte
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Other