Is diarrhoea during antibiotics expected, and when is it concerning?
Mild diarrhoea can occur with antibiotics, but it is not always harmless. C. difficile infection may develop during or after treatment. Severe or repeated diarrhoea, particularly with fever, pain, blood or dehydration, needs assessment rather than simply taking an antidiarrhoeal medicine.
Details
Report the antibiotic and timing
Give the medicine name, when diarrhoea began, stool frequency and any recent antibiotic exposure. Not every case is C. difficile; stool testing or examination depends on severity and risk factors.
Do not improvise prescription changes
The team decides whether to continue, stop or switch treatment by considering the original infection and new symptoms. Do not start leftover antibiotics. Seek advice before medicines that slow the bowel when severe infection, blood or fever is suspected.
Replace fluids and reduce spread
Drink frequently in manageable amounts and use appropriate oral rehydration when needed. Wash hands with soap and water after using the toilet and before eating. Reduced urine, marked dizziness or inability to drink needs prompt care, with earlier advice for older or immunocompromised people.
Related reading: What are the symptoms of food poisoning, and when is medical care needed?.