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C. diff (also called Clostridioides difficile or C. difficile, formerly known as Clostridium difficile) is a bacteria that causes infection in the colon (large intestine/bowel). The infection can cause severe diarrhea and inflammation in the colon, or colitis. C. diff infections can occur after a disruption to the balance of the gut microbiome—an ecosystem of microscopic organisms like bacteria, viruses, and fungi, sometimes called gut flora. Read more at our C. diff 101 page here.

If you believe you have C. diff, seek medical advice from your healthcare provider. If you are experiencing severe symptoms, call 911 or go to your nearest emergency department.

Yes. C. diff is contagious, as a bacterium that is spread through stool (also called feces or poop). Tiny particles of stool containing C. diff, can exist in soil and on surfaces (including hands, medical devices like thermometers or stethoscopes, clothing, toilets, and countertops, etc.). Although C. diff is common in the environment, normal gut bacteria and immunity helps to keep it in check. Most people will not develop C. diff infections even if they are exposed to C. diff. Why some people develop infection and others do not is not fully understood.

When exiting the body through stool, C. diff bacteria undergo a process called sporulation, in which they become inactive and develop a protective coating that makes them even harder to kill and allows them to survive for hours to “months or sometimes years.” If a person ingests these spores, they can introduce C. diff to their colon where it becomes active again and is able to cause infection.

For as long as it is present in stool, C. diff can be contagious. This means that even after a person is cured of the infection, if they remain colonized with the bacteria (known as asymptomatic colonization) they can transmit C. diff. This is why practicing good handwashing, using dedicated bathrooms, and using the right cleaning products is so important, especially in the home of someone with C. diff. Read more about protecting against C. diff in our Care Guide.

C. diff spores are so small that they are invisible to the naked eye (can only be seen under a microscope). Although there have been C. diff spores found in the air near C. diff patients, there is not enough research to say conclusively that it is airborne, and infection control authorities have not recommended any airborne precautions.

You can prevent contracting a C. diff infection by avoiding unnecessary use of antibiotics, which kill the normal bacteria that protect against C. difficile infection (read more about when antibiotics should be used for common infections here), minimizing stays in healthcare facilities, and practicing good handwashing techniques.

If you have a C. diff infection or you live with someone who has C. diff, you can prevent the spread of infection by practicing good hand hygiene and, if possible, dedicating one bathroom to be used only by the person with C. diff. For sanitizing surfaces and dirty laundry, the Centers for Disease Control and Prevention (CDC) recommends using 1 part bleach to 9 parts water as a homemade cleaning product similar to ones used in healthcare facilities. Consider wearing gloves to handle soiled linen, rinse any items with visible feces before washing, and always wash your hands after cleaning. More information on home cleaning can be found in our Care Guide.

The use of probiotics (foods and dietary supplements that contain cultures of one or more bacterial species) to prevent C. diff infections is somewhat controversial. The American College of Gastroenterology recommends against the use of probiotics for preventing C. diff infections in people taking antibiotics or for preventing recurrent C. diff, while the American Gastroenterological Association recommends the use of probiotics as prevention of C. diff infections.

Generally, those that recommend the use of probiotics for preventing C. diff tend to point towards probiotics containing Saccharomyces boulardii (S. boulardii), Lactobacillus species, and mixtures of a variety of probiotics as having positive outcomes for C. diff infections. You can learn more about choosing quality probiotics on our blog, “Choosing the best probiotic for C. diff.” Always consult your healthcare provider to determine if you should take probiotics.

Anyone can have C. diff bacteria introduced to their colon, most often by ingesting the spores, but there are some conditions (risk factors) that make it easier for the infection to take hold (meaning the colonization of C. diff causes symptoms).

The major risk factor for C. diff infections is recent antibiotic use. Antibiotics, specifically broad spectrum (which kill a wide variety of bacterial species) antibiotics, can leave a person vulnerable to C. diff by disrupting the gut microbiome. When a person’s microbiome is disrupted, it allows harmful bacteria to grow in numbers and damage the body’s systems; C. diff is one such bacterium. C. diff infections can also be very difficult to cure. Because the main treatment for it is an antibiotic, sometimes these drugs either cannot completely kill the C. diff or they kill too many of the other ‘good’ bacteria and C. diff easily repopulates the gut.

Other risk factors for C. diff include:

• Being 65 or older
• Recent stay at a hospital or nursing home
• A weakened immune system, such as people with HIV/AIDS, cancer, or organ transplant patients taking immunosuppressive drugs
• Previous infection with C. diff or known exposure to the bacteria

C. diff is different from other germs. It does not invade the body. When it is active, it makes toxins that damage the lining of the large intestine. C. diff causes toxic colitis. The body responds to the inflammation by pouring fluid into the intestine. That fluid is the diarrhea many people experience. The diarrhea can be terrible, but it helps flush out C. diff that the toxins out of the body. Doctors avoid giving antidiarrheal medicine for C. diff to avoid building up more C. diff and its toxins which can make the inflammation even worse.

Yes, nausea, and subsequently vomiting, are possible with C. diff infections.

While confusion is not a symptom of a C. diff infection on its own, some patients report feeling “brain fog.” Confusion or brain fog may be an indication of a more serious complication of C. diff—such as dehydration, damage to the bowels, or sepsis. If you or your loved one are experiencing confusion while or after battling C. diff, please seek medical attention as soon as possible.

Yes, C. diff can cause colitis. “Colitis” refers to inflammation in the colon, or large intestine/ bowel. When caused by an overgrowth of C. diff, this is known as pseudomembranous colitis. Symptoms of pseudomembranous colitis may include:

• Watery diarrhea
• Abdominal cramps, pain or tenderness
• Fever
• Pus or mucus in your stool
• Nausea
• Dehydration

Colitis, like most aspects of C. diff infections, can become life-threatening. If you believe you are suffering from colitis during or after a C. diff infection, seek medical attention.

Yes. C. diff may cause sepsis. Sepsis is the body’s extreme response to infection, and is considered a life-threatening medical emergency. If you believe you have sepsis, call 911 and seek care at your nearest emergency department.

C. diff can be fatal. Diarrhea from C. diff can cause severe dehydration which, left untreated, can be life-threatening.

Sepsis and toxic megacolon are two life-threatening potential complications of C. diff. Risk of dying from C. diff depends on a number of individual factors, like age, co-existing health conditions (comorbidities), and infection with ribotype 027, what is known as a hypervirulent strain of C. diff.

Sepsis (an extreme reaction to infection) is one potential complication of C. diff. Symptoms of sepsis include:

• Rapid breathing and heart rate
• Shortness of breath
• Confusion or disorientation
• Extreme pain or discomfort
• Fever, shivering, or feeling very cold
• Clammy or sweaty skin

To learn more about sepsis, visit Sepsis Alliance here.

Toxic megacolon, inflammation and swelling in the tissues of the colon—large intestine or bowel—that cause it to widen and cease function, is another dangerous risk of C. diff. Symptoms of toxic megacolon include:

• Swelling of the belly
• Pain in the belly
• Fever
• Rapid heart rate
• Shock
• Diarrhea

If you believe you have sepsis or toxic megacolon, call 911 and seek care at your nearest emergency department.

Diarrhea, caused by C. diff or not, is usually—if not always—loose and watery. Having frequent loose and watery stools is a known symptom of C. diff. For more help identifying and communicating to your healthcare provider what kind of stool you are experiencing, check out the Bristol Stool Chart here.

Stool is sometimes characterized as foul-smelling or sickeningly sweet-smelling with C. diff infections, but predicting C. diff based on odor is generally regarded as an urban myth. Every patient can experience symptoms differently, and in some cases the stool may not smell unusual at all.

If stool is black in color, it can be an indication of bleeding in the intestinal tract, which may require medical attention. Talk to your healthcare provider if you see black in your stool.

Tests available for diagnosing C. diff infections currently include molecular tests (polymerase-chain reaction or PCR tests), antigen tests (glutamate dehydrogenase or GDH tests), and toxin tests (cytotoxicity assays, enzyme immunoassays or EIAs, helicase-dependent amplifications or HDAs, and lateral flow immunoassays or LFIAs).

These tests are all conducted on stool samples. While blood tests can detect elevated levels of white blood cells (WBCs, also called leukocytes)—usually indicators of infection. However, high WBCs do not always indicate infection and infection might be present without causing elevated WBCs.

PCR tests identify C. diff by detecting its toxin-producing genes (toxigenic C. diff). PCR tests are quick and highly accurate, but may detect C. diff even when a patient does not have an active infection (asymptomatic colonization)—resulting in a false-positive.

GDH tests identify C. diff by detecting the antigen glutamate dehydrogenase, which is an enzyme produced by C. diff bacteria. Like in PCR testing, results may come back positive without there being an active C. diff infection. For this reason, GDH tests are usually paired with other types of tests like PCR, EIA, or cytotoxicity assays.

Toxin tests work by directly detecting the toxins produced by C. diff, which more accurately indicate active infection. C. diff produces toxins A and B; some tests detect toxin A, some detect toxin B, and some detect both toxin A and toxin B. The issue with toxin tests is that toxin samples (used in EIAs, HDAs, and LFIAs) are very fragile and may decay before being tested, possibly giving false-negatives.

Cytotoxicity assays, which use tissue samples to detect toxin B, have been historically regarded as the ‘gold standard,’ but are more costly, time-consuming, and require special expertise to perform, so they are not often used in clinical settings.

Additionally, sigmoidoscopies, colonoscopies, and radiology exams (x-rays and CT scans) can help in diagnosing C. diff infections and other gastrointestinal conditions.

If you believe you may have C. diff, seek medical attention as soon as possible to get tested and figure out the best treatment for you. For help finding a healthcare provider, visit our Find a Provider page.

C. diff can be cured by a number of methods. The following are treatments most often used in the U.S. for C. diff:

Antibiotics Many people are prescribed antibiotics for C. diff infections (yes, the same type of drug that often puts people at risk for C. diff can be used to treat it). Vancomycin (brand name Vancocin) and fidaxomicin (brand name Dificid) are currently the top-recommended antibiotic treatments for C. diff. Metronidazole (brand name Flagyl) is another antibiotic sometimes used to treat C. diff, but it is no longer recommended as a first-line treatment due to its decreased rate of success and increased risk of recurrent C. diff, especially compared to vancomycin and fidaxomicin. Read the most recent Infectious Disease Society of America (IDSA) clinical practice guidelines here for more information on treatment recommendations for healthcare professionals.

FMT In cases of a severe and/or recurrent C. diff infection, a person may have a fecal microbiota transplant, or FMT, in which the infected person receives stool from a healthy donor, usually via colonoscopy (this method may be preferred over enema or naso-gastric tube). These stool donations contain the bacteria found in the balanced gut of the donor, which help to replenish the populations of “good” bacteria in the patient’s colon. FMT was considered experimental by the Food and Drug Administration (FDA), meaning that clinicians may prescribe FMT under certain circumstances and with informed consent from the patient, but has now expanded that approval to include specific approaches. (Access to the procedure is often limited due to these regulations, the availability of donor stool or access to stool banks, and access to providers willing to prescribe FMT. – Is this still true?)

Microbiome Therapy There is an emerging treatment method known as microbiome therapy, which works by engineering the intestinal microbiome through a variety of methods. These treatments are currently available through participation in clinical trials. More information on clinical trials for C. diff treatments can be found here.

Monoclonal Antibodies Monoclonal antibodies, such as bezlotoxumab (brand name Zinplava), may also be prescribed as an adjunctive treatment alongside antibiotics. These are synthetic antibodies which bind C. difficile toxin to engage immunity to help fight a C. diff infection.

Read more at our Treatment Options page and in our Care Guide.

Your immune system may be able to fight off the infection on its own, but because C. diff infections can be life-threatening, always seek the advice of your primary care provider, infectious disease specialist, or gastroenterologist (GI doctor) on what treatment is best for you. Some individuals report success mitigating C. diff infections with the use of probiotics and other dietary supplements, but these methods have not been widely researched, or endorsed by clinical governing bodies in the U.S.

Yes. People with initial C. diff infections have a 10-20% chance of developing another (recurrent) infection. Recurrent C. diff cases are defined as an episode of symptoms coupled with a positive assay test result, from 2 to 8 weeks after a previous episode of symptoms and a positive assay test result. After a first recurrent infection, there is a 40-60% chance that C. diff will recur again. Recurrent C. diff infections pose an increased risk of death.

To combat recurrence, avoid unnecessary use of antibiotics and healthcare facilities, practice proper hygiene and cleaning in the home, and work to restore the microbiota in your gut through diet and nutrition.

If you believe you are experiencing recurrent C. diff, seek medical attention and get tested again as soon as possible.

Due to the possibility of developing post-infectious irritable bowel syndrome (PI-IBS), it can be hard to tell if your C. diff has been cured. Symptoms of PI-IBS may vary, but often include:

• fever
• diarrhea
• vomiting
• abdominal pain
• changes in the frequency of defecation
• changes in the appearance of stool

Many consider a test result negative for C. diff to mean that a C. diff infection has been cured; however, due to the different types of tests available for C. diff the results may be confusing or misleading. A negative result, or ‘clinical’ cure, also does not guarantee complete alleviation of symptoms.