From the Guidelines
For a colonoscopy, patients should use low-residue and low-fiber foods or full liquids for the early and midday meals on the day before colonoscopy when using a split-dose bowel preparation regimen, as recommended by the US Multi-Society Task Force on Colorectal Cancer 1. The most commonly used bowel preparation liquids include polyethylene glycol (PEG) solutions like GoLYTELY, MoviPrep, or MiraLAX, and sodium phosphate solutions such as Fleet Phospho-soda.
- The standard PEG regimen typically involves drinking 4 liters of solution the evening before the procedure, or split between the evening before and morning of the procedure.
- For MiraLAX, patients usually mix 238 grams with 64 ounces of clear liquid and drink it over several hours.
- Sodium picosulfate preparations like Prepopik require drinking smaller volumes (10 ounces) followed by additional clear liquids. These preparations work by drawing water into the colon and stimulating bowel movements to clear fecal matter, ensuring the physician has a clear view of the colon lining during the procedure. Patients should follow their doctor's specific instructions, which may include dietary restrictions (clear liquids only) for 24-48 hours before the procedure, avoiding red or purple liquids, and stopping solid foods the day before. Adequate hydration with clear liquids is essential throughout the preparation process to prevent dehydration from the laxative effects of these solutions, as supported by the US Multi-Society Task Force on Colorectal Cancer 1. It is also recommended to limit dietary modifications to the day before colonoscopy for ambulatory patients at low risk for inadequate bowel preparation, and to use a split-dose administration of bowel preparation purgatives for all patients, regardless of high-volume or low-volume preparation 1.
From the FDA Drug Label
(Bottle Only) (white section in cap) (17 g) (cold, hot or room temperature) then drink
(Packet Only)
stir and dissolve one packet of powder (17 g) in any 4 to 8 ounces of beverage (cold, hot or room temperature) then drink
Active Ingredient Magnesium citrate 1.745g per fl oz
Bowel Preparation Liquids for a colonoscopy include:
- Polyethylene glycol (PO): mix 17g of powder in 4 to 8 ounces of beverage 2
- Magnesium citrate (PO): contains 1.745g of magnesium citrate per fluid ounce 3
From the Research
Bowel Preparation Liquids for Colonoscopy
To prepare for a colonoscopy, several bowel preparation liquids can be used, including:
- Polyethylene glycol (PEG) solutions, such as GoLytely 4, 5
- Sodium phosphate solutions, such as Exelyte 6
- MiraLAX (PEG 3350 without electrolytes) combined with Gatorade and bisacodyl 4, 5
Characteristics of Each Liquid
- Polyethylene glycol solutions are still the most commonly used for preparation 7
- Sodium phosphate solutions have been associated with electrolyte and osmolarity imbalances and nephrocalcinosis, and their clinical use has been questioned 8
- MiraLAX-Gatorade bowel prep has been shown to be less effective than GoLytely in some studies 4, but similar in effectiveness in others 5
Patient Factors and Preparation Quality
- Patient factors, such as medical comorbidities and medication lists, can affect the quality of bowel preparation 7
- The use of scoring systems, such as the Boston Bowel Preparation Scale (BBPS), can help predict colon cleansing and guide the practitioner in timing of follow-up examination 7
- Documentation of preparation quality is essential to ensure thorough bowel cleansing and successful detection of colon polyps 7