Split-dosed MiraLAX/Gatorade Is an Effective, Safe, and Tolerable Option for Bowel Preparation in Low-Risk Patients: A Randomized Controlled Study

Am J Gastroenterol. 2012 Jul;107(7):1036-42. doi: 10.1038/ajg.2012.115. Epub 2012 May 8.


Objectives: MiraLAX with Gatorade is a low-volume bowel preparation regimen that has been used widely in community practice and is anecdotally better tolerated than Golytely. Despite its widespread use, there are little data on the efficacy and tolerability of this solution and no safety data in the literature. The primary aim of this study was to compare the efficacy, safety, and tolerability of single-dosed and split-dosed regimens of MiraLAX/Gatorade with Golytely for bowel preparation before colonoscopy.

Methods: Adults presenting for outpatient colonoscopy were screened for enrollment into this single-blinded randomized controlled trial. Patients with severe cardiac or renal disease and patients with electrolyte abnormalities were excluded. Subjects were randomized into four groups: 4 l Golytely single-dosed (Go-Si), 4 l Golytely split-dosed (Go-Sp), 238 g MiraLAX in 64 oz of Gatorade single-dosed (Mlax-Si), and MiraLAX/Gatorade split-dosed (Mlax-Sp) groups. Laboratory data including complete blood count, comprehensive metabolic panel, and osmolality were collected before the day of bowel preparation and just before the start of colonoscopy. Subjects completed a survey assessing taste and tolerability of the solution. Colonoscopies were recorded using video recording software and de-identified. Colonoscopy videos were evaluated for efficacy of cleansing by two blinded endoscopists. Two validated bowel preparation scales were used to assess bowel cleansing: the Boston Bowel Preparation Scale (BBPS; 0-9 best) and Ottawa Scale (0-14 worst).

Results: A total of 222 patients were evaluated in this study (86.2% male, mean age 59.4). Of these, 57 subjects were randomized to the Go-Si group, 51 to Go-Sp group, 60 to Mlax-Si group, and 54 to Mlax-Sp group. There was no significant difference in age, gender, or timing of colonoscopy between the groups (P>0.05). Mean BBPS scores were: Go-Si=6.07, Go-Sp=8.33, Mlax-Si=6.62, and Mlax-Sp=8.01. Mean Ottawa score for the groups were: Go-Si group=6.77, Go-Sp=4.12, Mlax-Si=6.25, and Mlax-Sp=4.8. Go-Sp resulted in significantly better cleansing than Go-Si (P<0.01). Mlax-Sp resulted in significantly better cleansing than Mlax-Si (P<0.01). There was no significant difference in BBPS between Go-Sp and Mlax-Sp. There were no clinically significant electrolyte changes from baseline in any subject in any group after bowel prep (P>0.05). Subjects rated the taste and overall experience of Mlax/Gatorade preparation better than Golytely (P<0.01). In all, 96.8% of Mlax/Gatorade subjects were willing to repeat the same preparation vs. 75% for Golytely subjects (P<0.01).

Conclusions: Split-dosed MiraLAX/Gatorade was an effective, safe, and tolerable option for bowel preparation before colonoscopy in the low-risk patients in this study. MiraLAX/Gatorade appears to be more tolerable than Golytely as a bowel cleansing regimen and was the preferred agent by the patients in this study.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Analysis of Variance
  • Cathartics / administration & dosage
  • Cathartics / pharmacology*
  • Colonoscopy*
  • Electrolytes / administration & dosage
  • Electrolytes / pharmacology*
  • Female
  • Humans
  • Isotonic Solutions / administration & dosage
  • Isotonic Solutions / pharmacology*
  • Male
  • Middle Aged
  • Polyethylene Glycols / administration & dosage
  • Polyethylene Glycols / pharmacology*
  • Risk Assessment
  • Single-Blind Method
  • Surface-Active Agents / administration & dosage
  • Surface-Active Agents / pharmacology*
  • Treatment Outcome


  • Cathartics
  • Electrolytes
  • Golytely
  • Isotonic Solutions
  • Surface-Active Agents
  • gatorade
  • Polyethylene Glycols