Diagnosis

Doctors often suspect C. difficile in anyone who has diarrhea and who has other risk factors for C. difficile. In such cases, doctors are likely to order one or more of the following tests.

Stool tests

Toxins produced by C. difficile bacteria can usually be detected in a sample of your stool. Several main types of lab tests exist, and they include:

  • Polymerase chain reaction. This sensitive molecular test can rapidly detect the C. difficile toxin B gene in a stool sample and is highly accurate.
  • GDH/EIA. Some hospitals use a glutamate dehydrogenase (GDH) test in conjunction with an enzyme immunoassay (EIA) test. GDH is a very sensitive assay and can accurately rule out the presence of C. difficile in stool samples.
  • Enzyme immunoassay. The enzyme immunoassay (EIA) test is faster than other tests but isn't sensitive enough to detect many infections and has a higher rate of falsely normal results. This is typically not the only test used.
  • Cell cytotoxicity assay. A cytotoxicity test looks for the effects of the C. difficile toxin on human cells grown in a culture. This type of test is sensitive, but it is less widely available, is more cumbersome to do and requires 24 to 48 hours for test results. It's typically used in research settings.

Testing for C. difficile is unnecessary if you're not having diarrhea or watery stools, and isn't helpful for follow-up treatment. If you aren't having diarrhea, stool shouldn't be tested for C. difficile.

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 and pseudomembranes.

Imaging tests

If your doctor is concerned about possible complications of C. difficile, 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, expansion of the bowel or, more rarely, a hole (perforation) in the lining of your colon.

Treatment

The first step in treating C. difficile is to stop taking the antibiotic that triggered the infection, when possible. Depending on the severity of your infection, treatment may include:

  • Antibiotics. Ironically, the standard treatment for C. difficile is another antibiotic. These antibiotics keep C. difficile from growing, which in turn treats diarrhea and other complications. Your doctor may prescribe vancomycin (Vancocin HCL, Firvanq) or fidaxomicin (Dificid).

    Metronidazole (Flagyl) may be rarely used if vancomycin or fidaxomicin aren't available.

  • Surgery. For people who have severe pain, organ failure, toxic megacolon or inflammation of the lining of the abdominal wall, surgery to remove the diseased portion of the colon may be the only option.

Recurrent infection

Up to 20% of people with C. difficile get sick again, either because the initial infection never went away or because they've been reinfected with a different strain of the bacteria.

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:

  • Antibiotics. Antibiotic therapy for recurrence may involve one or more courses of a medication. In general, guidelines recommend not repeating the same therapy used for an initial infection for a recurrent infection. The effectiveness of antibiotic therapy declines with each subsequent recurrence.
  • Fecal microbiota transplant (FMT). Also known as a stool transplant, FMT is emerging as an alternative strategy for treating recurrent C. difficile infections. Though FMT is considered experimental and is not yet approved by the FDA, clinical studies are currently underway.

    FMT restores healthy intestinal bacteria by placing another person's (donor's) stool in your colon through a colonoscope or nasogastric tube. 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.

  • Probiotics. Probiotics are organisms, such as bacteria and yeast, and are available over the counter. 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 C. difficile treatment or prevention 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.