C. diff infections are treated with specific antibiotics that target the bacteria while sparing the rest of your gut, and most people recover within 10 to 14 days of starting treatment. The first step is stopping whatever antibiotic triggered the infection in the first place, if possible. From there, treatment depends on whether this is your first episode, a recurrence, or a severe case.
First-Line Antibiotic Options
Two oral antibiotics are the standard treatments for an initial C. diff infection. The one your doctor chooses depends on your risk of the infection coming back.
Vancomycin, taken by mouth four times a day for 10 days, has been the workhorse treatment for years. It works well for clearing the active infection, but it has a notable weakness: recurrence rates are higher compared to the newer alternative. Fidaxomicin, taken twice a day for 10 days, is at least as effective at curing the initial infection and significantly better at preventing it from returning. A large meta-analysis found that fidaxomicin cut the 40-day recurrence rate roughly in half compared to vancomycin, and the advantage held at 60 and 90 days as well.
Fidaxomicin’s edge comes from its narrow targeting. It kills C. diff while leaving more of your healthy gut bacteria intact, which helps your microbiome recover faster and resist recolonization. Current guidelines from the Infectious Diseases Society of America favor fidaxomicin when it’s available, though vancomycin remains a solid option. Cost and insurance coverage sometimes determine which one you end up on, since fidaxomicin is considerably more expensive.
What Happens if the Infection Comes Back
Roughly 1 in 5 people who recover from C. diff will have a recurrence, and each recurrence raises the odds of another. Treatment for a second or third episode looks different from the first round.
One common approach is a vancomycin taper, where instead of stopping the antibiotic abruptly after 10 days, you gradually step it down. A typical taper starts with the standard dose four times a day for two weeks, then drops to twice a day for a week, then once a day for another week. This slow reduction gives your gut flora time to reestablish while keeping C. diff suppressed. An extended-pulsed course of fidaxomicin is another option: full doses twice daily for five days, then a single dose every other day for the next 20 days.
For people at high risk of recurrence, a monoclonal antibody called bezlotoxumab can be given as a one-time IV infusion alongside antibiotic treatment. It doesn’t kill C. diff directly. Instead, it neutralizes one of the toxins the bacteria produce, which reduces the damage to your intestinal lining and lowers the chance of the infection returning.
Microbiota-Based Therapies for Repeat Recurrences
When C. diff keeps coming back despite antibiotics, the underlying problem is usually a gut microbiome that’s too depleted to fight off reinfection on its own. Microbiota-based therapies address this by reintroducing healthy bacteria directly.
Fecal microbiota transplant (FMT) has the strongest track record. A systematic review of over 1,800 patients found a 91% success rate at eight weeks following FMT for recurrent C. diff. That translates to a number needed to treat of just 1.5, meaning nearly every patient who receives it benefits compared to standard antibiotics alone.
The FDA has also approved a standardized oral product called Vowst for preventing recurrence after antibiotic treatment. It’s a course of four capsules taken once daily for three consecutive days. In clinical trials, only 12.4% of people treated with Vowst had a recurrence through eight weeks, compared to nearly 40% of those who received a placebo. These products are typically reserved for people who’ve had two or more recurrences and haven’t responded to standard antibiotic strategies.
Treatment for Severe and Fulminant Cases
Most C. diff infections cause watery diarrhea, cramping, and sometimes a low-grade fever. Severe cases add signs like a very high white blood cell count or kidney problems. Fulminant C. diff, the most dangerous form, involves dangerously low blood pressure, shock, or a condition where the colon essentially stops moving.
Fulminant infections require aggressive treatment, typically in a hospital. The vancomycin dose is quadrupled compared to a standard case, and if the gut has stopped moving properly, the drug may also be delivered rectally to reach the colon directly. An IV antibiotic is added alongside to ensure the medication gets into the system even when the gut can’t absorb it normally. Surgery, including removal of most of the colon, becomes necessary in some fulminant cases when the infection doesn’t respond to medical treatment or when there’s a risk of the colon perforating.
Diet and Gut Recovery
What you eat during and after a C. diff infection matters more than most people realize. Research in animal models consistently shows that high-fiber diets lead to less severe disease and faster recovery, while low-fiber diets worsen outcomes. The reason ties back to your microbiome: fiber feeds the beneficial bacteria that compete with C. diff for space in your gut.
Not all fiber is equally helpful, though. Soluble, fermentable fibers appear to offer the most protection. Pectin (found in apples, citrus fruits, and berries) increased microbiome diversity and reduced inflammation markers in one study. Inulin, found in garlic, onions, and bananas, helped mice clear C. diff more efficiently. Fructooligosaccharides, present in many of the same foods, improved survival in another model. These are all types of “microbiota-accessible carbohydrates,” meaning your gut bacteria can actually break them down and use them for fuel.
During the acute phase of infection, when diarrhea is at its worst, you may need to start with gentler foods and gradually increase fiber as your symptoms improve. Staying hydrated is critical since the volume of diarrhea C. diff causes can lead to dehydration quickly. Plain water, broths, and oral rehydration solutions all help. Avoid sugary drinks and alcohol, which can irritate an already inflamed gut.
Preventing Spread and Reinfection
C. diff spreads through spores, and these spores are remarkably tough. Alcohol-based hand sanitizers do nothing against them. Alcohol kills bacteria in their active form but cannot destroy spores, which have a protective outer shell. Washing your hands with soap and water is the only reliable way to physically remove C. diff spores from your skin.
For cleaning surfaces at home, especially bathroom surfaces, you need a bleach solution. A 1:10 dilution of standard household bleach (which contains about 5 to 6% sodium hypochlorite) produces roughly 5,000 parts per million of chlorine, the concentration shown to kill C. diff spores within 10 minutes. Spray or wipe the surface and let it stay wet for at least that long before wiping it dry. Regular household cleaners without bleach won’t reliably eliminate the spores.
C. diff spores can survive on surfaces for months, so consistent cleaning matters, particularly if someone in the household is actively infected or recently recovered. Dedicate a bathroom to the infected person if possible, wash clothing and bedding in hot water, and keep bleach-based cleaning on a daily schedule until well after symptoms have resolved.