A diagnosis of C. difficile infection is based on the presence of:

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

People who have regular, formed stools should not be tested for C. difficile infection. Recent use of antibiotics is not required for making a diagnosis of C. difficile infection.

Stool tests

If C. difficile infection is suspected, your doctor will order one or more laboratory tests of a stool sample. These tests identify either the toxins or strains of the bacteria that produce toxins.

Colon examination

In rare instances, to help confirm a diagnosis of C. difficile infection and look for alternative causes of your symptoms, your doctor may examine the inside of your colon. This test (flexible sigmoidoscopy or colonoscopy) involves inserting a flexible tube with a small camera on one end into your colon to look for areas of inflammation or abnormal tissue.

Imaging tests

If your doctor is concerned about possible complications of C. difficile infection, he or she may order an abdominal X-ray or a computerized tomography (CT) scan, which provides images of your colon. The scan can detect the presence of complications such as:

  • Thickening of the colon wall
  • Enlargement of the bowel
  • A hole (perforation) in the lining of your colon.


Treatments are used only if a person has signs or symptoms of infection. People who carry the bacteria — but are not sick — are not treated.


If C. difficile infection is related to an antibiotic you're taking, your doctor will likely discontinue use of that drug. In many cases, however, an antibiotic treatment is critical for treating another infectious condition. Your doctor may prescribe a different antibiotic that is less likely to contribute to diarrhea related to C. difficile infection.

Antibiotics are the mainstay to treat C. difficile infection. Commonly used antibiotics include:

  • Vancomycin (Vancocin HCL, Firvanq)
  • Fidaxomicin (Dificid)

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


Surgery to remove the diseased portion of the colon may be necessary in some cases, including:

  • Severe pain
  • Organ failure
  • Toxic megacolon
  • Inflammation of the lining of the abdominal wall

Treatment for recurrent infection

Approximately 25% of people treated for C. difficile infection get sick again, either because the initial infection never went away or because they've been reinfected with a different strain of the bacteria. The risk increases with each C. difficile infection episode and exceeds 50% after three or more infections.

Your risk of recurrence is higher if you:

  • Are older than 65
  • Are taking other antibiotics for a different condition while being treated with antibiotics for C. difficile infection
  • Have a severe underlying medical disorder, such as chronic kidney failure, inflammatory bowel disease or chronic liver disease

Treatment for recurrent disease may include the following strategies.

  • Antibiotics. Antibiotic therapy for recurrent infections may involve one or more courses of a medication. The drugs are usually different from the type of antibiotic used previously. The effectiveness of antibiotic therapy declines with each subsequent recurrence.
  • Antibody-based therapy. A therapy, known as bezlotoxumab (Zinplava), is a human antibody against the C. difficile toxin B and has been shown to reduce the risk of recurrent C. difficile infection in those at a high risk of recurrence.
  • Fecal microbiota transplant (FMT). FMT is an emerging treatment for multiple recurrent C. difficile infection that 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 an experimental procedure. You need to sign an informed consent about the benefits and risks of the experimental procedure. FMT is also called a stool transplant or an intestinal microbiota transplant.

    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.

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

  • Probiotics. Probiotics are supplements or foods that contain microorganisms intended to maintain or improve the "good" bacteria in the body. The role of these products in C. difficile infection is controversial. Research hasn't consistently shown that currently available products are helpful in preventing or treating infection with C. difficile. Advanced probiotics are currently being studied for their potential use in the treatment or prevention of C. difficile infection but aren't currently available.

Lifestyle and home remedies

Supportive treatment for diarrhea includes:

  • Plenty of fluids. Choose fluids containing water, salt and sugar, such as diluted fruit juice, soft drinks and broths.
  • Good nutrition. If you have 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 your diarrhea clears up, you may have temporary difficulty digesting milk and milk-based products.