Treating C. diff (Clostridioides difficile infection) starts with stopping the antibiotics that likely caused it, if your doctor says it is safe. The standard treatment is a specific antibiotic like vancomycin or fidaxomicin taken for 10 days. Probiotics are not proven to help and some evidence suggests they may even make things worse. For repeat infections, a fecal microbiota transplant (FMT) is the most effective option available.
What Is C. Diff and Why Is It Hard to Treat?
C. diff is a bacterium that causes severe diarrhea and colitis. It happens when your gut microbiome is damaged, usually by other antibiotics. The bacteria produces toxins that attack the lining of your colon.
The reason C. diff is difficult to treat comes down to spores. C. diff forms spores that survive in the environment for months. They resist heat, cleaning products, and even some antibiotics. When you take antibiotics for another infection, those spores can wake up and start producing toxins again.
About 1 in 5 people who get C. diff will have a second infection. The risk goes up with each recurrence. This is why the first treatment matters so much.
What Are the First-Line Treatments for C. Diff?
Doctors have two main antibiotics for initial C. diff infections. Vancomycin has been the standard for years. Fidaxomicin is newer and costs more, but research published in the New England Journal of Medicine found it reduces recurrence rates compared to vancomycin.
For a first mild to moderate infection, metronidazole was once common. The Infectious Diseases Society of America now recommends vancomycin or fidaxomicin instead. Metronidazole is no longer considered first-line because it works less well.
Treatment usually lasts 10 to 14 days. Symptoms often improve within 2 to 3 days. But improvement does not mean the infection is gone. You must finish the full course even if you feel better.
How To Treat C. Diff When It Keeps Coming Back
Recurrent C. diff is a different problem from the first infection. The original antibiotics may not work as well the second or third time. This is where treatment changes.
For a first recurrence, doctors often use the same antibiotic but for a longer course, or they switch to the one you did not use before. A tapered or pulsed course of vancomycin can work better than a standard course. This means taking a lower dose over several weeks, then stopping and starting again.
For people with two or more recurrences, fecal microbiota transplant (FMT) is the most effective option. FMT involves transferring stool from a healthy donor into your colon. The goal is to restore the normal bacteria that keep C. diff from growing. Studies show FMT works in about 80 to 90 percent of people with recurrent infections.
There is also a newer FDA-approved product called fecal microbiota spores (Vowst). It works similarly to FMT but comes in capsules. The CDC reports that bezlotoxumab, an antibody infusion, can also help prevent recurrence in high-risk patients when given alongside antibiotics.
What Should You Eat and Avoid During C. Diff Treatment?
Your diet matters during a C. diff infection, but not in the way many articles claim. There is no special diet that kills C. diff or cures the infection. The goal is to give your gut a chance to heal while you take the antibiotics.
Diarrhea from C. diff causes fluid and electrolyte loss. You need to replace both. Water alone is not enough. Drinks with salt and sugar, like oral rehydration solutions, work better. Broth and diluted fruit juice also help.
Foods that are gentle on the colon include white rice, plain toast, bananas, applesauce, and cooked vegetables. These are low in fiber and less likely to irritate the gut lining. Avoid high-fiber foods like whole grains, raw vegetables, beans, and nuts during the active infection. Fiber can make diarrhea worse by pulling water into the colon.
Do not take probiotics. This is worth repeating. Research from the Journal of the American Medical Association found that probiotics did not prevent C. diff diarrhea in people taking antibiotics and may have caused harm in some cases. The idea that probiotics restore your gut is logical but the evidence does not support it for C. diff.
What Are the Side Effects of C. Diff Treatments?
Vancomycin and fidaxomicin are generally well tolerated. Nausea, abdominal pain, and mild diarrhea are the most common side effects. These symptoms are hard to separate from the infection itself.
Fidaxomicin has fewer side effects overall. The main downside is cost. A course can cost over $3,000 without insurance. Vancomycin is cheaper but requires prior authorization from some insurance plans.
FMT carries a small risk of infection if the donor stool contains pathogens. The FDA requires donor screening to reduce this risk. Some people report bloating or cramping after the procedure, but serious complications are rare when done through a regulated source.
Bezlotoxumab can cause infusion reactions like fever and chills. It is given as a single IV dose during antibiotic treatment. It does not treat the active infection. It only lowers the chance of it coming back.
How To Prevent Spreading C. Diff to Others
C. diff spores live on surfaces for months. They survive alcohol-based hand sanitizers. You must wash your hands with soap and water every time you use the bathroom. This is not optional.
Bleach kills C. diff spores. Clean bathroom surfaces, toilets, and any areas where stool may have touched with a bleach-based cleaner. Regular household cleaners do not work. The CDC recommends a 1:10 dilution of bleach to water for disinfecting.
If you live with others, use a separate bathroom if possible. Wash clothes and bedding in hot water with bleach. Do not share towels or razors. Stay home from work or school until you have had no diarrhea for at least 48 hours.
People over 65 and those with weakened immune systems are at highest risk. If you live with someone in this group, take extra care with cleaning and handwashing.
Comparison of C. Diff Treatment Options
| Treatment | Used For | Success Rate | Main Drawback |
|---|---|---|---|
| Vancomycin | First infection or first recurrence | About 75-80% | Higher recurrence rate than fidaxomicin |
| Fidaxomicin | First infection | About 80-85% | High cost |
| Fecal transplant (FMT) | Recurrent infections (2+) | 80-90% | Requires procedure; donor screening needed |
| Bezlotoxumab | Preventing recurrence in high-risk patients | Reduces recurrence by about 10% | IV infusion; does not treat active infection |
| Probiotics | Not recommended | No proven benefit | May cause harm in some cases |
Common Misconceptions About Treating C. Diff
The biggest myth is that probiotics can treat or prevent C. diff. This has been studied extensively. The results are clear: probiotics do not help and may increase the risk of infection in people with compromised immune systems. Do not take them during or after treatment unless your doctor specifically advises it.
Another common belief is that you should stop the antibiotic once diarrhea improves. This is wrong. Stopping early allows the infection to return stronger. You must finish the entire course as prescribed.
Some people think C. diff is contagious like a cold. It is not airborne. You catch it by ingesting spores from contaminated surfaces or hands. Good handwashing with soap and water is the main prevention. Alcohol gel does not kill spores.
There is also a belief that C. diff always comes back. This is not true. Most people recover fully after one round of treatment. The risk of recurrence is higher in older adults, people in hospitals, and those who continue taking other antibiotics.
Frequently Asked Questions
How long does it take to recover from C. diff?
Most people feel better within 2 to 3 days of starting antibiotics, but full recovery takes 1 to 2 weeks.
Can C. diff go away on its own without treatment?
Mild cases in otherwise healthy people sometimes resolve without antibiotics, but this is rare and not recommended because the infection can become severe quickly.
What happens if C. diff is not treated?
Untreated C. diff can lead to severe dehydration, toxic megacolon, bowel perforation, and death in rare cases.
Is it safe to take probiotics with C. diff antibiotics?
No. Current evidence does not support probiotics for C. diff, and they may cause harm, especially in people with weakened immune systems.
