Clostridium difficile infection

Also called C. diff infection

Clostridium difficile is a type of bacteria that can cause infection, most often in older adults or people who are in hospital or have recently had antibiotics.

On this page, you can find the following information:

Key points

  1. Infection with Clostridium difficile (sometimes called 'C. diff') most often occurs in people who have recently had a course of antibiotics and are in hospital.
  2. Symptoms can range from mild diarrhoea to a life-threatening inflammation of your bowel.
  3. Very mild cases may get better on their own, otherwise, treatment with specific antibiotics is generally needed. 
  4. Symptoms come back in around 1 in 5 cases and treatment may need to be repeated.
  5. C. diff is contagious. Washing your hands with soap and water, especially after using the toilet and before eating or drinking, is especially important in reducing the spread of and preventing C. diff infection.

What is Clostridium difficile (C. diff)?

C. diff bacteria are found in the gut of about 1 in every 30 healthy adults. The bacteria usually live harmlessly without causing you to become ill because other bacteria normally found in your bowel keep them under control. But some antibiotics can interfere with the balance of bacteria, which can cause the C. diff bacteria to multiply and produce toxins. This causes diarrhoea and makes you feel unwell. 

C. diff can spread easily to other people because the bacteria are passed out of your body in your diarrhoea. 
Someone with a C. diff infection is generally considered to be infectious until at least 48 hours after their symptoms have cleared up.

Who is at risk of getting C. diff infection?

Healthy people usually don't get C. diff infections. You're more likely to get this infection after you have antibiotics, are over 65 years of age or are in hospital or a long-term care facility (nursing home).

Factors that increase your risk of C. diff infection

  • Taking antibiotics: Taking antibiotics can increase your risk of C. diff infection, especially if you have been taking antibiotics that work against several types of bacteria (broad-spectrum antibiotics) or several different antibiotics at the same time, or taking antibiotics long term. You're also at greater risk of getting this disease if you have low immunity.
  • Being in hospital or in a nursing home: This increases the risk of C. diff infection. Many cases start in the community, especially in nursing homes. Generally the longer your stay in hospital and the older you are, the greater your risk of developing C. diff infection.
  • Older adults: C. diff infection is more common in older people. More than 8 in 10 cases occur in people over the age of 65. This is partly because older people are more commonly in hospital. Also, older people seem to be more prone to this infection possibly due to weakened immune systems or having other medical problems that put you at greater risk. Infection is less likely in children.
  • Previous C. diff infection: If you have had C. diff infection once, you are at higher risk of having the infection again in the future. Having had the C. diff infection can make your bowel more sensitive to antibiotics.

How is C. diff spread?

C. diff can spread easily to other people because the bacteria are passed out of your body in your diarrhoea. Once out of your body, the bacteria turn into spores (bacteria with a protective coating). These are designed to survive outside the human body.

They can survive for a very long time on surfaces (such as toilets, commodes and bed frames), objects and clothing. If these aren't thoroughly cleaned, they can infect someone else.

C. diff can also spread on your hands if you have direct contact with someone who is infected or if you touch contaminated surfaces. If you then touch your mouth, you may swallow the spores.

What are the symptoms of C. diff infection?

The main symptom is having at least 3 watery poos daily for 2 days or more. Other symptoms include fever, loss of appetite, nausea and stomach pain or cramp. There are different strains of C. diff and some can cause a more serious illness than others. 

In most cases, the symptoms start within a few days of starting the antibiotic. However, in some cases, symptoms develop up to 10 weeks after finishing a course of an antibiotic.

How is C. diff infection diagnosed?

if your doctor suspects you have a C. diff infection, a faeces (poo) sample can be tested in the laboratory to confirm the diagnosis. The test looks for the toxin (poison) that is produced by C. diff in the poo sample. Blood tests, an X-ray of your abdomen (tummy) or a CT scan may be suggested if you have more severe infection.

How is C. diff infection treated?

The decision whether to treat C. diff infection and the type of treatment depends on the severity of the illness. No treatment is needed if you have no symptoms but are known to carry the bacteria in your gut.

If you have symptoms you will usually be treated with a specific antibiotic (usually metronidazole). It is important you complete the whole course of antibiotics or the infection may come back. Occasionally in severe cases, surgery is required to remove the infected bowel.

How can I avoid spreading C. diff infection?

Good hand hygiene is especially important to reduce the risk of spreading C. diff infection. This includes washing your hands with soap and water, especially after using the toilet and before eating or drinking.

Washing your hands with soap and water is better at preventing the spread of diarrhoea than using alcohol-based hand rubs.

Once the diarrhoea stops, the risks of spreading C. diff infection are much lower. Read more about hand washing.

If you're in hospital

If you are in hospital, you'll be placed in isolation to reduce the risk of spreading C. diff infection to other patients. This means you'll be in your own room and have your own toilet. Hospital staff caring for you may wear gloves and gowns or aprons to prevent them carrying the bacteria to other patients. If you're in isolation, don't visit patients in other parts of the ward or in other wards. You may also be asked not to go into public areas.

Healthy visitors, including pregnant women, can carry on visiting you in hospital as they aren't at an increased risk of infection. But your visitors must wash their hands with soap and water when they leave your room. It's unlikely that the bacteria will be transmitted if everyone keeps up good hand hygiene. Your family can take your laundry home and wash it as usual.

C. diff infection won't stop you going home from hospital. You'll be discharged as soon as your general condition allows. Complete your course of antibiotics as prescribed even if you are feeling better. 

At home, maintain good personal hygiene and household cleaning. Good hand washing is very important. Wash your hands well after using the toilet and before eating. Keep the toilet clean. Clean surfaces in bathrooms, kitchens and other areas regularly with household detergents and disinfectants. If your symptoms come back, go to your GP as you may need further treatment. 

Learn more

What is C. diff? Center for Disease Control, US
Clostridium difficile Patient Info, UK


  1. Clostridioides difficile (C. diff) Center for Disease Control, US
  2. Clostridium difficile colitis Antibiotic Guide, BPAC, NZ, 2017

Information for healthcare providers

Clostridium difficile infection – the Australian experience – Professor Tom Riley, Department of Microbiology, University of Western Australia, 2013
An Australian national approach to C difficile – Dr Marilyn Cruickshank, Program Director, Australian Commission on Safety and Quality in Health Care (ACSQHC), 2013
Clostridium difficile infection – NZ perspective – Dr Sally Roberts, Infectious Diseases Physician and Clinical Microbiologist, Auckland DHB and HQSC, 2019
Clostridium difficile infection (CDI) – issues around surveillance and notifiability – Dr John Holmes, Public Health Medicine Specialist, ESR and University of Otago, 2019

Credits: Health Navigator Editorial Team . Reviewed By: Dr Veronica Playle, Clinical microbiologist; Dr Jeremy Steinberg, GP Last reviewed: 26 Nov 2019