What medications cause diarrhea?
Last updated September 3, 2026.
The NIH's list: antibiotics, magnesium-containing antacids, and cancer medicines cause acute diarrhea, with metformin the everyday addition and sugar alcohols like sorbitol in liquid medicines the sneaky one. Antibiotics loosen things by killing gut bacteria, usually settling after the course; severe or bloody diarrhea on antibiotics needs a prompt call since C. difficile is the dangerous version. Fixes favor formulation over quitting: extended-release metformin, tablets instead of liquids. Hydrate through it, and get seen for diarrhea with blood, fever, or persistence past the drug course.
What to do
- Tell the prescriber rather than quitting mid-course.
- Ask about formulation changes: XR versions, tablets over liquids.
- Hydrate; dehydration is the real danger.
- Call promptly for bloody or severe diarrhea on antibiotics.
Related questions
- How to stop diarrhea fast?
- How long does a stomach bug last?
- Why does spicy food cause diarrhea?
- Why do I get diarrhea when nervous?
