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Clostridium difficile (C. difficile) infection (CDI)
C. Difficile Infection (CDI) Overview
- What is C. difficile?
Diarrhea is a common side effect of taking antibiotics, occurring 10–20% of the time. It usually gets better when you stop taking the antibiotics. Clostridioides difficile infection (CDI) is caused by a type of bacteria that makes toxins. This bacterium can cause a serious kind of diarrhea related to antibiotics. The illness ranges from mild diarrhea to very severe swelling in the colon, which can even be deadly. CDI usually occurs when antibiotics have changed the normal bacteria in the colon, allowing the C. difficile bacteria to grow and produce toxins. Since 2000, the number and seriousness of C. difficile infections (CDI) have increased in the US, Canada and other parts of the world. C. difficile is a type of bacteria that is found is everywhere in the environment, and produces spores that are hard to kill. C. difficile produces two main toxins - toxins A and B - that cause swelling in the colon.
Risk Factors
- What are the risk factors for C. difficile infection?
The main risk for getting a C. difficile infection is recently taking antibiotics. However, the infection can happen even without prior antibiotic use. Some antibiotics, like clindamycin, cephalosporins, and quinolones (i.e. ciprofloxaxin, levofloxacin), are more likely to cause CDI. Other risks for the infection include being of older age, having a weak immune system, having other illnesses, and being in a hospital or nursing home. However, even healthy individuals who have not had antibiotics can get CDI. People with Crohn’s disease or ulcerative colitis are more likely to get CDI, and may be sicker than patients with IBD alone or CDI alone. Some studies suggest that taking medicine to reduce stomach acid, like proton pump inhibitors, may increase the chances of getting CDI. C. difficile can be picked up by touching spores in the environment, especially in hospitals. People who are infected can spread spores, and it can spread between patients in hospitals.
Symptoms
- What are the symptoms of CDI?
Symptoms of a C. difficile infection can be different for each person. The most common symptom is diarrhea, which is usually watery and sometimes, but rarely, bloody. It can cause crampy stomach pain. Other symptoms include fever, nausea, and vomiting. More serious disease may cause high fever, abdominal tenderness and/or tenderness.
Screening/Diagnosis
- How is C. difficile infection diagnosed?
Doctors might suspect C. difficile if a person has new, unexplained diarrhea that occurs more than 3 times per day. To confirm the diagnosis, doctors use stool tests. There are several stool tests that can be used to diagnose C. difficile infections, but the three most commonly used tests are: GDH, Toxin EIA and Toxin B PCR. Your physician can order these tests at most commercial labs.
Treatment
- How is C. difficile infection treated?
First, if possible, it is best to stop the antibiotic that led to the infection. However, this may not always be possible, because some infections, like severe bone or heart infections, need long-term antibiotics. Treatment for C. difficile can depend on how bad or severe is the infection. Mild infections are usually treated with antibiotics that people take at home. Often vancomycin or fidaxomicin are taken for 10 days.
Most people feel better after taking antibiotics for CDI. If diarrhea does not improve with treatment, your doctor may need to look for other causes of diarrhea. Antidiarrheal drugs are not recommended to treat C. difficile infection and should only be used after talking with your doctor.
When a C. difficile infection is severe, it can cause serious problems like kidney injury and an increase in white blood cells. Patients with severe infections are usually very sick and may have symptoms like fever, abdominal pain, tenderness and dehydration. Often, patients with severe infection need to be hospitalized. Just like mild infections, severe C difficile infections should be treated with vancomycin or fidaxomicin.
C. difficile can become very severe, or what doctors call “fulminant.” If this happens, it can cause serious problems like shock, low blood pressure, or a condition called toxic megacolon. Toxic megacolon means the large intestine gets very swollen and might even tear. People with very severe CDI have higher chances of dying due to their infection. Often people with very severe CDI are treated with higher doses of vancomycin, and are watched closely in intensive care. A surgeon might need to remove the colon to save the person’s life.
While antibiotics work for most cases of C. difficile infection, symptoms can recur in 10-20% of cases after treatment ends. This is called recurrent CDI and typically occurs 1–2 weeks after treatment ends. After one recurrence, the likelihood of further recurrences goes up to 40-60%. Treatment for recurrent CDI often includes a vancomycin taper over six to eight weeks or fidaxomicin for ten days. The most effective treatment, however, is fecal microbiota transplant (FMT). FMT is typically given via capsules or rectal suspension. Traditional FMT may be done via colonoscopy where stool from a healthy donor is instilled into the colon of a patient with recurrent CDI. In studies, it has been effective in over 90% of patients who received the treatment, and has been proven effective with several randomized controlled trials.
Prevention
- Can C. difficile infection be prevented?
Using antibiotics carefully and only when necessary helps minimize the chances of C. difficile infection from happening. Wise antibiotic policies, by using narrow-spectrum agents when directed and avoiding unnecessary use of broad-spectrum antibiotics, are key in the prevention of CDI. Environmental cleaning is important – especially hand washing with soap and water, since alcohol gels do not inactivate spores. In hospitals, everyone entering the room of a patient with CDI should wear a gown, gloves, and use disposable equipment.
Author(s) and Publication Date(s)
Christina M. Surawicz, MD, MACG, University of Washington School of Medicine, Seattle, WA – Published December 2012, Updated July 2016
Ari Grinspan, MD, Mount Sinai, New York, NY – Updated April 2021
Ryan T. Hoff, DO, PeaceHealth Gastroenterology, Vancouver, WA – Updated April 2025