Macrogol / Polyethylene glycol
Polyethylene glycol
Also known as: Klean-Prep · Moviprep · PEG · Polyethylene glycol · Macrogol 3350 · Macrogol 4000
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Dosing by species
Dosing data for this drug is not yet available in the VetSheet formulary. Every other section below is complete. Consult the current product label before prescribing.
Overview
Bowel cleansing solutions contain polyethylene glycol (macrogol) as an osmotic laxative and balanced electrolytes to maintain isotonicity and prevent net fluid loss or gain. When administered orally, they rapidly empty the bowel.
Clinical Pearl: Commonly used for bowel preparation prior to colonoscopy, gastrointestinal radiography, or surgery, and occasionally for the management of severe refractory constipation or fecal impaction.
Mechanism of action
Polyethylene glycol acts as an osmotic laxative. It is a large, non-absorbable polymer that binds water → retains fluid within the colonic lumen → increases fecal volume and softens stool → stimulates colonic motility and peristalsis → rapidly empties the bowel. The addition of balanced electrolytes ensures isotonicity, preventing significant shifts of sodium, potassium, or water across the intestinal mucosa.
Safety & warnings
Contraindications
- Gastrointestinal obstruction
- Bowel perforation
- Gastric retention
- Toxic megacolon
- Severe dehydration
Adverse effects
- Nausea
- Vomiting
- Abdominal cramping
- Bloating
- Fluid and electrolyte imbalances (rare if formulated with electrolytes)
Precautions
Use with caution in patients with an impaired gag reflex or those at risk of aspiration. Ensure the patient is adequately hydrated before administration. Do not add flavorings or other substances to the reconstituted solution as it may alter the osmolarity.
Drug interactions
Decreased absorption due to rapid gastrointestinal transit time
Monitoring
- Fecal output and consistency
- Hydration status
- Serum electrolytes (in prolonged or high-dose use)
Pharmacokinetics
Absorption
Minimal to no systemic absorption following oral administration.
Distribution
Remains locally in the gastrointestinal tract.
Metabolism
Not metabolized.
Elimination
Excreted unchanged in the feces.
Overdose
Overdosage may result in severe diarrhea, leading to significant fluid and electrolyte loss. Treatment is primarily supportive, focusing on intravenous fluid therapy to restore hydration and correct any electrolyte derangements.
Available products
Formulations
- Oral powder for reconstitution
Human-labeled
- Klean-Prep powder for reconstitution
- Moviprep powder for reconstitution
Regulatory status
Human-approved products used off-label in veterinary medicine.
Human-approved products used off-label.
Available as a Pharmacy (P) medicine for humans, but veterinary use typically requires a prescription under the cascade.
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store unmixed powder at room temperature. Once reconstituted with water, store the solution in the refrigerator and discard any unused portion after 24 to 48 hours (check specific manufacturer guidelines).
Client information
Mix the powder exactly as directed with the appropriate amount of water. Do not add any flavorings or mix with food. Allow your pet frequent access to an appropriate area to defecate, as this medication will cause rapid, watery stools. Ensure your pet has access to fresh drinking water unless instructed otherwise by your veterinarian.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.