Obesity does not affect sodium picosulphate bowel preparation

Intern Med J. 2012 Dec;42(12):1324-9. doi: 10.1111/j.1445-5994.2012.02865.x.


Background: A previous study utilising oral polyethylene-glycol by Borg et al. concluded that obesity is an independent predictor of inadequate bowel preparation at colonoscopy.

Aim: To compare bowel preparation quality between obese and non-obese individuals as assessed by Boston bowel preparation scale (BBPS) after using sodium picosulphate.

Methods: Prospective recruitment of patients at a day surgical unit in a New South Wales academic hospital. Bowel preparation was with Picoprep in all patients. Body Mass Index and epidemiological details were collected. Bowel preparation efficacy was assessed using the Boston Bowel Preparation Score.

Results: One hundred and four patients were enrolled prospectively. Five (4.8%) were excluded owing to poor mental capacity. Sixty-three (64%) were non-obese, and 36 (36%) were obese. Fifty-seven (90%) non-obese and 32 (89%) obese patients had good bowel preparation. There was no statistical difference for sodium picosulphate bowel preparation between obese and non-obese individuals (P > 0.99) using Fisher's exact probability tests. The BBPS score in the left colon predicted the overall BBPS score in all patients (P < 0.001). Three of 99 patients (3%) did not tolerate sodium picosulphate, with nausea being the most common side-effect.

Limitations: Non-randomised study

Conclusions: There was no difference in bowel preparation quality between obese and non-obese patients using a low-volume bowel preparation (sodium picosulphate) and without dose modification of the bowel preparation. Sodium picosulphate was a welltolerated and an effective bowel preparation for obese individuals. With an increasing incidence of obesity and expanding colonoscopic indications within Australia and other Western countries from government-sponsored programs, it is paramount that procedural quality not be compromised in the obese patient.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Body Mass Index
  • Cathartics*
  • Citrates / therapeutic use*
  • Colonoscopy*
  • Humans
  • Male
  • Middle Aged
  • Obesity*
  • Organometallic Compounds / therapeutic use*
  • Picolines / therapeutic use*
  • Young Adult


  • Cathartics
  • Citrates
  • Organometallic Compounds
  • Picolines
  • picosulfate sodium