An Overview of C. Diff

A highly contagious "bad" gut bacteria that can cause watery diarrhea

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Clostridioides difficile (C. diff for short) is a type of bacteria that normally lives in the gastrointestinal (GI) tract of around 3% of the population. If the balance of bacteria in your GI tract is disturbed, such as when taking antibiotics, C. diff can flourish.

Once it begins to take over, C. diff releases toxins that irritate the lining of the large intestine. This irritation causes the main symptoms of C. diff infection, which include watery diarrhea and abdominal cramping.

When a person has these symptoms along with certain risk factors (such as taking antibiotics or a recent hospital stay) their healthcare provider may suspect a diagnosis of C. diff.

Clostridium difficile bacteria

The treatment for C. diff includes taking antibiotics that kill the C. diff bacteria, maintaining adequate fluid intake, and monitoring for improvement. In the rare case that the infection becomes life-threatening, surgery to remove the colon can be necessary.

According to the Centers for Disease Control and Prevention, C. diff causes nearly half a million illnesses in the United States each year.


C. diff infections tend to occur when there is an imbalance of bacteria in the human gut, which allows C. diff to grow and release toxins. There are several factors that can throw off the balance of gut flora, but the one most commonly linked to C. diff infection is taking antibiotics.

These antibiotics work by targeting and killing bacteria in the area where there is an infection. The problem is, these medications also affect the balance of bacteria in the intestines. When antibiotics affect the balance of bacteria in the colon, but do not kill C. diff, it can flourish and cause symptoms.

However, C. diff can be quite hardy. What's more troubling is that certain strains are becoming increasingly resistant to antibiotics.


C. diff infections can develop during a course of antibiotics or after. The more doses a person takes, and the longer the antibiotic needs to be taken, the higher the risk of infection.

Research has found that several antibiotics seem to be associated with C. diff infection. Potentially higher-risk antibiotics include:

  • Cleocin (clindamycin)
  • Fluoroquinolones, such as Cipro (ciprofloxacin)
  • Carbapenem-type drugs, such as Primaxin (imipenem)
  • Cephalosporins

Taking these antibiotics does not mean you will definitely develop a C. diff infection, as there are other factors that influence your risk. Research has shown that the risk of C. diff associated with antibiotic use is greater in hospitalized patients taking high doses of the medications. However, any antibiotic can cause C. diff, and occasionally, it occurs in people who have taken no antibiotics.


C. diff is shed in feces and can be easily spread in whatever environment it's found in. Hospitals and nursing homes are common locations where C. diff can thrive.

The bacteria can live on bedrails, linens, commodes, bathroom door handles, floors, electronic rectal thermometers, and other medical equipment.

People in hospitals and long-term care facilities are more likely to be exposed to C. diff and have a higher risk of infection.

Other Factors

Research has also identified other factors that may increase the risk of C. diff infection.


The cardinal symptom of a C. diff infection is diarrhea, specifically loose, watery stools that occur frequently throughout the day. The diarrhea is often accompanied by abdominal cramping.

Other symptoms of C. diff infection may include:

  • Fever
  • Nausea
  • Loss of appetite

Complications of a C. diff infection are rare but may include:

It's fairly common to have diarrhea while (or after) taking an antibiotic. In most cases, C. diff is not the culprit. However, if you are experiencing significant diarrhea and other symptoms of the infection, call your healthcare provider.


A diagnosis of C. diff is usually confirmed by a positive stool test. A stool sample is needed for the test, which looks for toxins produced by C. diff (called toxin A and toxin B) OR the gene that encodes toxin.

Medical History

Often, a patient's medical history is sufficient to make a healthcare provider suspect infection with C. diff. For instance, a patient with diarrhea who is in the hospital and is taking, or has recently taken, antibiotics would prompt a healthcare provider to test for C. diff.

Laboratory Test

A diagnosis of C. diff is usually confirmed by a positive stool test. A stool sample is needed for the test, which looks for toxins produced by C. diff (called toxin A and toxin B) as well as the gene that encodes toxin B.

In some cases, other tests are needed to diagnose C. diff infection. These tests require more steps, take longer, and might need to be performed at a special lab.

A healthcare provider may want to order one of these tests to find out if someone who doesn't feel sick has C. diff—especially if the person cares for or works closely with others, such as a daycare worker or nurse.

About 3% of healthy adults, and a higher percentage of sicker adults, are colonized with the bacteria C. diff, but they don't have symptoms. They can still spread the bacterium to others.

Accurate and timely diagnosis and treatment of C. diff is not only important to helping someone manage their symptoms and reduce the risk of complications, but it's also necessary to prevent the infection's spread.


The treatment of an infection with C. diff may require multiple steps. The type of treatment and its duration will depend on how severe the infection is, and a person's overall state of health.

  • Stopping the inciting antibiotic: Discontinuing antibiotic treatment may not be possible; a healthcare provider will weigh the risks and benefits of doing so if someone is diagnosed with C. diff.
  • Hydration and electrolyte replacement: Fluids can be given orally (by mouth) at home. In more severe cases, a person might need to go to the hospital for fluid replacement intravenously (through the vein).
  • Antibiotic Administration: Even though antibiotic use can lead to C. diff, certain antibiotics can be helpful in treating the infection. Most patients with C. diff can be prescribed a course of Flagyl (metronidazole), vancomycin, or Dificid (fidaxomicin). The treatment may need to be repeated if the infection doesn't get better or comes back.
  • Surgery: Only 1% of all patients with C. diff. and 30% with severe disease will require surgery.

Infection Severity

The severity of a C. diff infection varies from person to person. While most people who contract C. diff in the hospital will be treated successfully, the infection can be life-threatening, particularly for people who are immunocompromised or otherwise already ill.

In severe cases, a person with C. diff infection might need to be admitted to the hospital and kept under close medical care for days or weeks. Rarely, a person might need to have their colon removed (colectomy) if the infection has caused damage.


It's important to note that C. diff can reoccur—about one in five people with C. diff will get it again. For a first-time recurrence of C. diff, an antibiotic regimen with oral vancomycin or oral fidaxomicin is recommended.

If someone has multiple, persistent, and severe C. diff infections, fecal microbiota transplantation (FMT) might be recommended. For FMT, stool from a healthy donor is delivered through colonoscopy or oral capsules into the gastrointestinal tract of someone who gets recurrent C. diff infections.

In November 2022, the FDA approved the first fecal microbiota product, Rebyota. Rebyota is approved for the prevention of the recurrence of C. difficile infections in adults who have completed antibiotic treatment for recurrent C. difficile infections. 


C. diff is highly contagious. However, there are precautions you can take to protect yourself if you're around someone who is sick or in an environment where C. diff is known to proliferate, such as a hospital or nursing home.

  • Wash your hands properly after using the bathroom and before eating. Scrub your hands and fingers thoroughly with soap and warm water for 30 to 40 seconds (the time it takes to sing the "Happy Birthday" song twice).
  • Wash any linens, clothing (especially underwear), and towels that a sick person has had contact with. Use hot water with laundry soap and chlorine bleach. 
  • Wipe down all hard surfaces in your home (light switch plates; toilet seats and flushers; oven and refrigerator handles; doorknobs; computer touchpads, etc.) with a bleach-based cleaning product. You can also mix one part bleach to 10 parts water.
  • If you are in a hospital or clinic, make sure that all healthcare providers are using precautions (wearing gowns and gloves) while caring for a person with C. diff. (hand sanitizer does not kill C. diff). Precautions should be started as soon as C. diff is suspected. Since the infection spreads easily, healthcare workers do not have to wait for a lab test to confirm the diagnosis before taking preventative action.

A Word From Verywell

If you are taking an antibiotic, finished a course of antibiotics within the last month, have been in the hospital recently or are currently in the hospital and you develop diarrhea, notify your healthcare provider. While there are many causes of diarrhea, it's important to rule out C. diff or confirm the infection as soon as possible.

Severe cases of C. diff are not common, but they can be life-threatening if they do occur. The infection can be treated and doing so will help you avoid complications, such as dehydration.

You can also prevent the infection from spreading and protect yourself from getting it by using proper hand hygiene techniques and workplace precautions if you could be exposed to C. diff at your job.

14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Trisha Torrey
 Trisha Torrey is a patient empowerment and advocacy consultant. She has written several books about patient advocacy and how to best navigate the healthcare system.