A diagnosis of C. difficile infection is based on having:

  • Diarrhea.
  • Other symptoms of C. difficile infection.
  • C. difficile in a stool sample.

People who have regular, formed stools should not be tested for C. difficile infection. Some people get C. difficile infection without having taken antibiotics. So recent use of antibiotics is not needed for making a diagnosis of C. difficile infection.

Stool tests

If C. difficile infection is suspected, one or more tests of a stool sample can show either the toxins or strains of the bacteria that produce toxins.

Colon exam

Rarely, to help confirm a diagnosis of C. difficile infection, a health care provider might check the inside of the colon. Tests used are either flexible sigmoidoscopy or colonoscopy. The tests involve putting a flexible tube with a small camera on one end into the colon to look for problem areas. These tests also can look for other causes of the symptoms.

Imaging tests

An X-ray of the stomach area or a CT scan can look for possible complications of C. difficile infection. These imaging tests can detect:

  • Thickened colon wall.
  • Enlarged bowel.
  • A hole, called a perforation, in the lining of the colon.


Treatments are used only for symptoms of infection. People who carry the bacteria but aren't sick don't get treated.


If C. difficile infection is related to an antibiotic, a health care provider will likely stop its use. Often, however, an antibiotic is needed to treat another infectious condition. A switch to another antibiotic might be less likely to cause diarrhea related to C. difficile infection.

Antibiotics are the main treatment for C. difficile infection. Commonly used antibiotics include:

  • Vancomycin (Firvanq Kit).
  • Fidaxomicin (Dificid).

Metronidazole (Flagyl) may be used with vancomycin to treat serious C. difficile infection.


Surgery to remove the diseased part of the colon may be needed if there's:

  • Severe pain.
  • Organ failure.
  • Toxic megacolon.
  • Swelling and irritation, called inflammation, of the lining of the wall around the stomach area.

Treatment for repeat infection

About 25% of people treated for C. difficile infection get sick again. The reason might be that the first infection never went away or that bacteria cause a new infection. The risk increases with each C. difficile infection. After three or more infections, the risk of another infection is greater than 50%.

Risk of repeat infection is higher for people who:

  • Are older than 65.
  • Are taking other antibiotics for another condition while on antibiotics for C. difficile infection.
  • Have a severe medical condition, such as chronic kidney failure, inflammatory bowel disease or chronic liver disease.

Treatment for C. difficile infection that comes back might include the following:

  • Antibiotics. Treatment for repeat infections may involve one or more courses of an antibiotic. The antibiotic is often different from the one used at first. Antibiotic therapy works less well each time the infection comes back.
  • Antibody-based therapy. A therapy known as bezlotoxumab (Zinplava) is a human antibody against C. difficile toxin B. It has been shown to cut the risk of repeat C. difficile infection in those at high risk of repeat episodes.
  • Fecal microbiota transplant (FMT). FMT is a newer treatment for C. difficile infection that keeps coming back. FMT has been studied in clinical trials. The U.S. Food and Drug Administration has not approved FMT but allows the use of FMT for C. difficile infection as a test.

    FMT restores healthy intestinal bacteria by placing another person's (donor's) stool in your colon with specialized tubes inserted through your rectum. Donors are screened for medical conditions, their blood is tested for infections, and stools are carefully screened for parasites, viruses and other infectious bacteria before being used for FMT.

    Someone getting an FMT might need to sign consent form about the benefits and risks of the treatment. FMT also is called a stool transplant or an intestinal microbiota transplant.

    FMT restores healthy intestinal bacteria by placing another person's, called a donor's, stool in the colon with special tubes put into the rectum. Donors are screened for medical conditions, their blood is tested for infections, and stools are carefully screened for parasites, viruses and other infectious bacteria before being used for FMT.

    Research has shown that FMT done one or more times has a success rate higher than 85% for treating C. difficile infections that keep coming back.

  • Probiotics. Probiotics are supplements or foods that have microorganisms to keep or improve the "good" bacteria in the body. The role of these products in C. difficile infection is not clear. Not all the research has shown that probiotics are helpful in preventing or treating infection with C. difficile.

    Researchers are studying advanced probiotics for treatment or prevention of C. difficile infection. These products aren't offered outside of research studies.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Lifestyle and home remedies

Supportive treatment for diarrhea includes:

  • Plenty of fluids. Choose fluids that have water, salt and sugar, such as diluted fruit juice, soft drinks and broths.
  • Good nutrition. For watery diarrhea, eat starchy foods, such as potatoes, noodles, rice, wheat and oatmeal. Other good choices are saltine crackers, bananas, soup and boiled vegetables. If you aren't hungry, you may need a liquid diet at first. After the diarrhea clears up, you might have trouble digesting milk and milk-based products for a while.

C. difficile infection care at Mayo Clinic

Sept. 01, 2023
  1. Clostridioides (formerly Clostridium) difficile-induced diarrhea. Merck Manual Professional Version https://www.merckmanuals.com/professional/infectious-diseases/anaerobic-bacteria/clostridioides-formerly-clostridium-difficile%E2%80%93induced-diarrhea?. Accessed March 21, 2023.
  2. Lamont JT, et al. Clostridium difficile in adults: Epidemiology, microbiology, and pathophysiology. https://www.uptodate.com/contents/search. Accessed March 21, 2023.
  3. Frequently asked questions about Clostridium difficile for healthcare providers. Centers for Disease Control and Prevention. https://www.cdc.gov/cdiff/clinicians/faq.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fhai%2Forganisms%2Fcdiff%2Fcdiff_faqs_hcp.html. Accessed March 21, 2023.
  4. Guh AY, et al. Trends in U.S. burden of Clostridioides difficile infection and outcomes. New England Journal of Medicine. 2020; doi:10.1056/NEJMoa1910215.
  5. Lamont T, et al. Clostridium difficile in adults: Clinical manifestations and diagnosis. https://www.uptodate.com/contents/search. Accessed March 21, 2023.
  6. Loscalzo J, et al., eds. Clostridium difficile infection, including pseudomembranous colitis. In: Harrison's Principles of Internal Medicine. 21st ed. McGraw Hill; 2022. https://accessmedicine.mhmedical.com. Accessed March 21, 2023.
  7. McDonald LC, et al. Clinical practice guidelines for Clostridium difficile infection in adults and children: 2017 update by the Infectious Diseases Society of America (ISDA) and Society for Healthcare Epidemiology of America (SHEA). Clinical Infectious Diseases. 2018;66:987.
  8. AskMayoExpert. Clostridium difficile infection (adult). Mayo Clinic; 2022.
  9. Kelly CP, et al. Clostridium difficile in adults: Treatment. https://www.uptodate.com/contents/search. Accessed March 21, 2023.
  10. Saleh MM, et al. Colitis-induced TH17 cells increase the risk for severe subsequent Clostridium difficile infection. Cell Host and Microbe. 2019;25:756.
  11. Taur Y, et al. Reconstitution of the gut microbiota of antibiotic-treated patients by autologous fecal microbiota transplant. Science Translational Medicine. 2018;10:9489.
  12. Diet strategies for managing chronic diarrhea. International Foundation for Gastrointestinal Disorders. https://iffgd.org/gi-disorders/diarrhea/nutrition-strategies/. March 22, 2023.
  13. Tariq R, et al. Experience and outcomes at a specialized Clostridium difficile clinical practice. Mayo Clinic Proceedings Innovations Quality and Outcomes. 2017;1:49.
  14. Khanna S, et al. Current and future trends in clostridioides (clostridium) difficile infection management. Anaerobe. 2019; doi:10.1016/j.anaerobe.2019.04.010.
  15. Feldman M, et al., eds. Antibiotic-associated diarrhea and Clostridioides difficile infection. In: Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 11th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed May 25, 2021.
  16. Johnson S, et al. Clinical practice guideline by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA): 2021 focused update guidelines on management of Clostridioides difficile infection in adults. Clinical Infectious Diseases. 2021; doi:10.1093/cid/ciab549.