C. diff colitis is inflammation of a person’s colon due to contagious bacteria. Most people with C. diff colitis fully recover, but in rare cases the condition can be life threatening.

Clostridioides difficile, which people commonly refer to as C. diff, is a germ that often causes mild stomach-based symptoms. In some cases, C. diff can cause serious or fatal complications, including colitis (inflammation of the colon).

It is possible for someone with C. diff to be asymptomatic. This means they can carry the toxin that produces C. diff and transmit it to others, but they do not experience symptoms.

In this article, we will explore what C. diff colitis is, the symptoms of C. diff colitis, whether it is contagious, its causes and risk factors, and its diagnosis and treatment. We will also answer some frequently asked questions about C. diff colitis.

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Colitis occurs when the lining of a person’s large intestine, or colon, becomes inflamed and swollen. Colitis has many possible causes, including C. diff infection (CDI). People can develop a CDI as a result of taking antibiotics. They may also contract C. diff during a hospital stay.

The Centers for Disease Control and Prevention (CDC) estimate that C. diff causes almost 500,000 infections per year in the United States. In up to 8% of cases, a person’s C. diff colitis may become life threatening.

People with a CDI may develop the following symptoms a few days after taking antibiotics:

However, in some people, symptoms may take several months to appear.

If a person’s CDI causes C. diff colitis to develop, they may experience additional symptoms. Common additional mild symptoms of C. diff colitis include abdominal cramps and leukocytosis, which is a high white blood cell count.

In 3–8% of cases, pseudomembranous colitis — which is often the result of C. diff — can develop into a fulminant infection. The onset of fulminant disease symptoms can occur very quickly. These symptoms can include:

Some of these complications, such as toxic megacolon and septic shock, are life threatening. People with these complications need immediate medical treatment.

C. diff is highly contagious. People with a CDI carry germs in their stool and can spread them if they do not follow proper hygiene practices. C. diff germs can live on people’s skin and other surfaces.

People who carry C. diff without symptoms can spread it to others without becoming ill themselves. To avoid spreading C. diff, people should:

  • wash their hands with soap and water every time they use the bathroom and before eating
  • use a separate bathroom from others if they have diarrhea
  • take showers and wash with soap

Alcohol-based hand sanitizers are not as effective for preventing the spread of C. diff as washing with soap.

Most cases of C. diff and C. diff colitis happen when people take or stop taking antibiotics. People are 7–10 times more likely to develop a CDI when taking antibiotics.

Antibiotics treat bacterial infections by eliminating harmful bacteria in a person’s body. However, they sometimes also eliminate helpful bacteria that protect people from infections such as C. diff.

People may be at greater risk of a CDI if they:

  • are over 65 years old
  • have recently stayed in a nursing home or healthcare facility
  • have a weakened immune system because of a condition such as cancer or HIV
  • are taking immunosuppressive drugs after an organ transplant
  • have had a previous CDI
  • have had exposure to C. diff germs
  • have been taking antibiotics for longer than a week

But people who do not have any of these risk factors can still develop a CDI.

Doctors diagnose a CDI by reviewing a person’s symptoms and using a stool test.

However, people may have C. diff germs in their body that are not causing an infection, and these germs may not be the cause of a person’s symptoms. A stool test and a review of symptoms will help doctors diagnose C. diff or other potential causes of a person’s symptoms.

Doctors treat a CDI using specific antibiotics that target the infection, such as:

  • fidaxomicin
  • oral vancomycin, as the intravenous form is not effective
  • metronidazole, generally if other treatments are not effective

Doctors usually instruct people to take these antibiotics for 10 days. A person’s C. diff symptoms should improve within a few days.

Doctors may tell a person to stop taking antibiotics that may have caused their CDI.

People can develop C. diff more than once. If a person’s CDI returns two or more times, doctors may offer them a fecal microbiota transplant. During this transplant, doctors give a person bacteria from the stool of someone without C. diff. This bacteria helps stop a person’s CDI.

If a person’s C. diff colitis becomes severe, they may need a colectomy surgery. During this procedure, a doctor removes some or all of a person’s colon. Doctors will perform this surgery to prevent a person’s colitis from becoming life threatening.

Here are some of the most frequently asked questions about C. diff and C. diff colitis.

How serious is C. diff colitis?

C. diff colitis can be a very serious condition. Only 1–3% of all CDIs lead to C. diff colitis. However, C. diff colitis can cause serious and life threatening complications.

Are C. diff and colitis the same thing?

No. C. diff is an infectious bacteria, or germ. Colitis is inflammation of a person’s colon, which the C. diff bacteria can cause.

Is there a cure for C. diff colitis?

Yes. But people who receive successful treatment for C. diff can develop it again.

Can people get C. diff more than once?

Yes. About 1 in 6 people who have had C. diff. develop another CDI 2–8 weeks after their initial infection. People who have had C. diff two or more times are more likely to develop the infection again or have a relapse of the initial infection.

How can someone tell if C. diff is getting better?

People with a CDI usually stop experiencing symptoms as their infection gets better. However, even if a person does not have symptoms, they may be able to transmit the infection to others and should practice good hand hygiene. This stops the spread of the germs to other people.

What does C. diff poop look like?

Clinicians often consider green poop to be a sign of C. diff. However, in a 2019 study, researchers assessed the stool colors of people with C. diff infections and found no statistically significant correlation between C. diff infections and a person’s poop color.

The researchers did note that the study’s sample size was small and that they had not considered other factors, such as diet.

Symptomatic CDI can also cause stools to be liquid and have a strong, distinctive odor.

C. diff colitis is a serious and life threatening condition caused by a C. diff bacterial infection. People may get C. diff infections when they come into contact with C. diff bacteria or take antibiotics that can allow the overgrowth of the bacteria.

People can help stop the spread of C. diff and prevent cases of C. diff colitis by washing their hands frequently.