Comparison Between Asymmetric And Standard Split-Dose Regimen For Bowel Preparation
Condition: Polyps; Colon Preparation
Study type: Interventional

Summary: 
      We aimed to compare the efficacy for bowel cleansing of a split-dose regimen with a low
      morning dose of PEG solution (Asymmetric; 25% of the dose is given on the day of the
      procedure and 75% of the dose is given on the day before) with the standard split-dose
      regimen in patients undergoing screening and surveillance colonoscopy using a low volume
      bowel preparation (2L PEG-citrate-simethicone plus Bisacodyl). We enrolled consecutive
      outpatients undergoing screening and surveillance colonoscopy in a randomized, single-blind,
      non-inferiority clinical trial. Patients were randomly assigned to: group A, asymmetric split
      dose regimen (1,5 L of PEG + bisacodyl the day before and 0,5 L 4 hours before colonoscopy);
      group B, symmetric split dose regimen (1 L of PEG + bisacodyl the day before and 1 L 5 hours
      before colonoscopy). Primary endpoint was the proportion of adequate bowel cleansing.
      Moreover, all patients filled in a nurse-administered questionnaire assessing compliance,
      tolerability and safety of bowel preparation.
    

Detailed description: 
      Prospective, randomized, single-blind, non-inferiority trial in adult patients undergoing
      screening or surveillance colonoscopy. Eligible participants were randomly assigned,
      according to a computer-generated list with an allocation ratio of 1:1, to receive either
      asymmetric or symmetric split-dose regimen of a low-volume preparation by investigators who
      were not involved in the enrolment process. Detailed written instructions were administered
      to all patients who accepted to participate. A low-fiber diet was prescribed three day before
      colonoscopy; participants in both groups were instructed to have a light lunch on the day
      before the colonoscopy and only clear liquid were allowed on the day of the exam. All
      endoscopic procedures were scheduled between 9:00 AM and 1:00 PM.

      The preparation used in the study is a combination of a 2 L sulphate-free iso-osmotic
      formulation of of PEG-4000 added with citrates and simethicone (PEG-CS) (Lovol-esse;
      AlfaWassermann, Bologna, Italy. Kit contains 4 pouches, each containing 64.5gr of PEG, to be
      dissolved in 2 L of water.), and bisacodyl 5 mg tablets (Lovodyl; Alfa-Wassermann, Bologna,
      Italy).

      All subjects were instructed to take 4 bisacodyl tablets at 4:00 PM on the day before the
      procedure. Subjects allocated to the asymmetric split-dose regimen group were invited to
      consume at 6:00 PM on the evening before the colonoscopy 3 sachets of PEG-CS in 1,5 L of
      water in a range from 90 to 120 minutes (about 250 mL every 15 min) and 4 hours before the
      scheduled procedure 1 sachets in 0,5 L of water in a range from 15 to 30 minutes. Subjects
      allocated to the symmetric split-dose regimen group were invited to consume at 6:00 PM on the
      evening before the colonoscopy 2 sachets of PEG-CS in 1 L of water in a range from 60 to 90
      minutes and 5 hours before the scheduled procedure 2 sachets in 1 L of water in a range from
      60 to 90 minutes.

      Unblinded investigators collected demographic and clinical data with medical history. All
      patients filled in a nurse-administered questionnaire to assess compliance, tolerability and
      safety of bowel preparation.

      Blinded experencied endoscopists performed endoscopic procedure in accordance with
      colonoscopy quality practice. Data on bowel cleansing (evaluated by using Boston Bowel
      Preparation Scale), endoscopic procedures and findings (i.e. cancer, polyps, diverticula)
      were collected.
    

Intervention name(s): PEG-4000 added with citrates and simethicone (PEG-CS) plus Bisacodyl
Intervention type(s): Drug
Intervention description(s): PEG-4000 added with citrates and simethicone (PEG-CS) (Kit contains 4 pouches, each containing 64.5gr of PEG) and bisacodyl 5 mg tablets
Intervention MeSH terms: Simethicone; Bisacodyl
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Colon cleansing