Polyethylene Glycol (PEG) and Electrolytes

PEG and electrolytes are oral solutions used prior to colonoscopy and other examinations or procedures to cleanse the intestines, in particular, the large bowel or colon. The PEG remains in the intestines where it retains water by producing an osmotic effect. This causes a watery stool, in fact, diarrhea, which rapidly cleanses the bowel within hours. Polyethylene 3350 is used in all of the formulations. Since electrolytes (sodium, potassium, etc.) are lost with diarrhea, electrolytes are added to the PEG to replace or prevent the losses. The electrolytes and their concentrations may vary from product-to-product. PEG and electrolyte containing products are mixed with water and drunk for the cleanse.

Examples of PEG and electrolytes brand names are:

• peg/electrolyte (Colyte)
• peg/electrolyte (Gavilyte-C)
• peg/electrolyte (Golytely)
• peg/electrolyte (Nulytely)
• polyethylene glycol 3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate, and ascorbic acid oral solution (Moviprep)
• peg-3350, sodium chloride, sodium bicarbonate and potassium chloride for oral solution (Trilyte)

Side effects of PEG and electrolytes are:

• nausea,
• abdominal fullness,
• bloating,
• stomach cramps,
• gas,
• vomiting,
• dizziness,
• headache, and
• anal irritation.

Oral medications administered within one hour of the start of PEG and electrolytes may be flushed from the body and may not be absorbed.

PEG and electrolytes are available as oral powder for solution.

• Colyte, Golytely, and Gavilyte contain polyethylene glycol 3350, sodium chloride, potassium chloride, sodium bicarbonate, and sodium sulfate.
• Moviprep contains polyethylene glycol 3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate and ascorbic acid.
• Nulytely contains polyethylene glycol 3350, sodium chloride, sodium bicarbonate and potassium chloride.
• Trilyte contains polyethylene glycol 3350, sodium chloride, sodium bicarbonate and potassium chloride.
• Colyte, Nulytely and Trilyte are available with flavor packs.

The FDA classifies PEG and electrolytes as pregnancy category C, which means that there is no evidence of safe and effective use of PEG and electrolytes for pregnant women. PEG and electrolytes should be given to pregnant women only if clearly needed.

It is not known whether PEG and electrolytes enter breast milk; therefore, PEG and electrolytes must be used with caution in mothers who are breastfeeding.