The bowel cleansing for colonoscopy. A randomized trial comparing three methods

Ann Ital Chir. 2006 Mar-Apr;77(2):143-6; discussion 147.


Introduction: Colonoscopy is the procedure of choice for the detection and ablation of small lesions o the colonic mucosa. A proper bowel cleansing is mandatory. So far several regimens have been proposed but rather none has shown a clear-cut advantage over the others. Aim of this study was to compare cleansing ability and patients' compliance of three oral regimens.

Patients and methods: Two-hundred and seventy-three patients were block randomised into three groups. Group A (92 patients) received tablets containing senna 12 mg and Magnesium Sulphate 15 mg the day before colonoscopy. Group B (98 patients) received a Polyethylene Glycol-based solution of two litres plus 4 tablets of Bisacodyl the day before the exam. Group C (83 patients) received Sodium Phosphate 40 milliliters the day before and the day of colonoscopy. Results of 265 patients were available for the analysis. Eight patients were excluded because inability to follow prescription. The lower incidence of constipation in group C was not significant. The other parameters were homogeneously distributed in the three groups.

Results: The 79 patients of the group C achieved a better bowel cleansing as compared with the 90 of group A (p = 0.0003) and the 96 of group B (p = 0.034). Constipated patients had a significantly better cleansing with Sodium Phosphate preparation compared with senna plus Magnesium Sulphate (p = 0.017), but not significantly better compared with Golytely solution. Compliance and rate of total colonoscopy performed were not statistically different in the three groups.

Conclusions: Sodium Phosphate solution gave better bowel preparation, with the same compliance, than either senna or Polyethylene solution. In constipated patients Sodium Phosphate showed good efficacy resulting in good cleansing rates similar to that of non-constipated patients. The poor results obtained by Polyethylene were related to the little amount of solution taken even if associated to Bisacodyl.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Anthraquinones / administration & dosage
  • Bisacodyl / administration & dosage
  • Cathartics / administration & dosage*
  • Chi-Square Distribution
  • Colonoscopy*
  • Electrolytes / administration & dosage
  • Female
  • Humans
  • Magnesium Sulfate / administration & dosage
  • Male
  • Middle Aged
  • Patient Compliance
  • Phosphates*
  • Polyethylene Glycols / administration & dosage
  • Preoperative Care
  • Senna Extract / administration & dosage
  • Sennosides
  • Solutions
  • Solvents / administration & dosage


  • Anthraquinones
  • Cathartics
  • Electrolytes
  • Golytely
  • Phosphates
  • Sennosides
  • Solutions
  • Solvents
  • Bisacodyl
  • Polyethylene Glycols
  • Magnesium Sulfate
  • Senna Extract
  • sodium phosphate