C. difficile is a bacterium that can cause diarrhoea and colitis, usually after antibiotics. It is treatable with specific antibiotics. Its spores spread easily, and soap and water, not alcohol gel, remove them from hands.

What is it?

Clostridioides difficile (C. difficile or C. diff) lives harmlessly in the gut of some people. When antibiotics disturb the normal balance of gut bacteria, it can multiply and release toxins that inflame the large bowel (colitis).

Who is at risk?

• Recent antibiotic use, especially in the past three months
• Hospital stays or living in a care facility
• Age over 65
• A weakened immune system, or medicines that suppress immunity
• Inflammatory bowel disease
• Long-term acid-reducing medicines (proton pump inhibitors), which may add to the risk

Symptoms

• Watery diarrhoea, three or more times a day, often with a distinctive smell
• Abdominal cramps and tenderness
• Fever, loss of appetite, nausea
• In severe cases: dehydration, abdominal swelling, and fewer stools because the bowel has stopped moving (this is a warning sign, not improvement)

Diagnosis and treatment

• Diagnosis is made with a stool test
• Treatment is a course of an oral antibiotic that targets C. difficile, usually vancomycin or fidaxomicin, for 10 days
• If possible, the antibiotic that triggered the infection is stopped
• Drink plenty of fluids; use oral rehydration solution if diarrhoea is heavy
• Do not take anti-diarrhoeal medicines such as loperamide unless your doctor advises it
• Your doctor may review acid-reducing medicines

If it comes back

About one in five people have a recurrence, usually within eight weeks. Recurrences are treated with a different course or regimen. For repeated recurrences, faecal microbiota transplantation (transfer of healthy gut bacteria from a screened donor) is highly effective and may be offered at specialist centres.

Preventing spread

• Wash hands with soap and water after using the toilet and before eating. Alcohol gel does not kill the spores
• Clean the toilet, taps and door handles daily with a chlorine-based (bleach) cleaner while you have symptoms
• Wash soiled clothes and bedding separately on a hot cycle
• Use a separate towel
• Tell any doctor who prescribes antibiotics in future that you have had C. difficile

Common questions

This leaflet is general information and does not replace advice from your own doctor. Version 1.0, October 2026. Next review October 2028.