Bisacodyl and Polyethylene Glycol 3350: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Bisacodyl
Polyethylene Glycol 3350
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of mucosal ulceration or ischemic colitis
Interaction Deep Dive
Concurrent use of stimulant laxatives and polyethylene glycol-containing colonoscopy preparations may increase the risk of mucosal ulceration or ischemic colitis; avoid use of stimulant laxatives (eg, bisacodyl, sodium picosulfate) while taking polyethylene glycol-containing colonoscopy preparations12.
Why it happens (mechanism)
Unknown
Common questions
Can I take Bisacodyl and Polyethylene Glycol 3350 together?
Increased risk of mucosal ulceration or ischemic colitis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Bisacodyl and Polyethylene Glycol 3350 interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Bisacodyl or Polyethylene Glycol 3350 need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: MOVIPREP(R) oral solution, polyethylene glycol 3350 sodium sulfate sodium chloride potassium chloride sodium ascorbate ascorbic acid oral solution. Salix Pharmaceuticals Inc (per FDA), Bridgewater, NJ, 2018. DailyMed
- Product Information: PLENVU(R) powder for oral solution, polyethylene glycol 3350, sodium ascorbate, sodium sulfate, ascorbic acid, sodium chloride, potassium chloride powder for oral solution. Salix Pharmaceuticals Ltd (per FDA), Bridgewater, NJ, 2018. DailyMed
Keep reading about Bisacodyl
Keep reading about Polyethylene Glycol 3350
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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