Bisacodyl
4,4'-(2-Pyridinylmethylene)bis(phenol) diacetate
Also known as: Dulcolax · Fleet Bisacodyl · Entrolax
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Constipation / Bowel Evacuation | — | PO | — | — | 🌎 NA |
| Constipation | 5-15 mg/dog | PO/Rectal | prn | — | 🌍 EU |
- Constipation / Bowel Evacuation: Listed for Dogs (D) in monograph index.
- Constipation: Empirical dose. Onset of action 6-10 hours (oral) or 15-60 minutes (rectal).
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Constipation / Bowel Evacuation | — | PO | — | — | 🌎 NA |
| Constipation | 2-5 mg/cat | PO/Rectal | prn | — | 🌍 EU |
- Constipation / Bowel Evacuation: Listed for Cats (C) in monograph index.
- Constipation: Empirical dose. Onset of action 6-10 hours (oral) or 15-60 minutes (rectal).
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Bisacodyl is a stimulant laxative used primarily in veterinary medicine for the treatment of constipation or for bowel evacuation prior to surgical, radiographic, or endoscopic procedures.
- Clinical Pearl: Because it is a stimulant laxative, it should be used for short-term management only. Chronic use can lead to dependency, loss of normal bowel function, and severe electrolyte imbalances.
Mechanism of action
Bisacodyl acts directly on the enteric nervous system.
- Stimulates mucosal sensory nerve endings → increases parasympathetic reflexes → enhances peristaltic contractions.
- Alters fluid and electrolyte absorption → increases intestinal fluid accumulation, which helps soften the stool and facilitate evacuation.
Safety & warnings
Contraindications
- Intestinal obstruction
- Ileus
- Gastrointestinal bleeding
- Severe dehydration
Adverse effects
- Abdominal cramping
- Diarrhea
- Nausea
- Electrolyte imbalances (with chronic use)
Precautions
Warning: Do not crush or chew enteric-coated tablets. Administer whole to prevent severe gastric irritation.
- Use with caution in dehydrated animals; ensure adequate hydration before and during therapy.
- Avoid concurrent administration with milk or dairy products.
Drug interactions
Premature dissolution of the enteric coating, leading to severe gastric irritation and vomiting.
Increased gastric pH may cause premature release of the drug in the stomach.
Monitoring
- Fecal output and consistency
- Hydration status
- Electrolytes (if used for prolonged periods)
Pharmacokinetics
Half-life
Absorption
Minimal systemic absorption following oral or rectal administration.
Distribution
Acts locally in the gastrointestinal tract.
Metabolism
Hydrolyzed by intestinal enzymes to the active desacetyl metabolite.
Elimination
Excreted primarily in feces; small amounts absorbed are excreted in urine as glucuronide conjugates.
Overdose
Overdose may lead to severe diarrhea, abdominal cramping, and significant fluid and electrolyte loss (especially hypokalemia). Treatment is supportive, focusing on intravenous fluid therapy and electrolyte replacement.
Available products
Formulations
- Tablets (enteric-coated)
- Enema
- Suppository
Human-labeled
- Bisacodyl 5 mg enteric-coated tablets
- Bisacodyl 10 mg suppositories
- Bisacodyl 10 mg/30 mL enema
Regulatory status
Available as Pharmacy (P) medicine.
Available as Pharmacy (P) medicine.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature (15-30°C) in a tight, light-resistant container. Protect suppositories from heat.
Client information
Important: Do not crush or chew the tablets. Give the medication exactly as prescribed.
- Ensure your pet has access to plenty of fresh water at all times.
- Contact your veterinarian if you notice severe diarrhea, signs of abdominal pain, or if no bowel movement occurs within 24 hours of administration.
- Do not give this medication with milk or antacids.
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.