Recurrent C. diff infection is when you contract a C. diff infection 2 to 8 weeks after completing treatment for a previous one. C. diff relapse is a recurrence of the same strain, while reinfection is of a different strain.

Clostridioides difficile (C. diff) is a type of bacteria that may lead to severe diarrhea and colon inflammation. It’s often associated with taking antibiotics.

According to the Centers for Disease Control and Prevention (CDC), 1 in 6 people experience a recurring infection within 2 to 8 weeks of the initial infection.

There are two types of recurring C. diff infections:

  • Relapse: The previous infection recurs due to contracting the same C. diff strain.
  • Reinfection: You contract a different C. diff strain than the initial strain, causing a new infection.

Once the first recurrence has resolved, the risk of another recurrence increases.

Around 4 in 10 people will experience a second recurrence after recovering from their first. The recurrence rate is 45% to 65% in people with more than two recurrences of C. diff.

Keep reading to learn more about the causes, symptoms, and risk factors of C. diff recurrence, and how to prevent it.

C. diff infections most commonly occur when you’re taking antibiotics. These medications kill both the bad and good germs in your body, which includes those responsible for fighting off infections.

As a result, you’re more likely to contract a C. diff infection if you come into contact with C. diff germs while taking antibiotics because you don’t have enough antibodies to fight the infection.

The effects of antibiotics may last for a couple of months. This may explain why many people experience C. diff recurrence within 8 weeks of a prior infection.

That said, the reason for C. diff recurrence isn’t fully understood. Researchers believe several factors may increase your risk of infections, such as having:

  • remaining spores persisting after the initial infection (relapse)
  • a weakened immune system
  • altered gut microbiome from taking antibiotics

There are a number of potential risk factors that make a C. diff recurrence more likely. Some of these you can’t control, but others may be managed to help reduce the risk of recurrence.

Older age

Being over 65 years old is one of the most commonly reported risk factors for recurrent C. diff infection.

According to the CDC, 1 in 11 people over age 65 years with a C. diff infection die within 1 month of diagnosis.

Researchers aren’t entirely clear why older people may have a higher recurrence rate than younger people, but it may be due to their weaker immune systems and the higher prevalence of other medical conditions.

Antibiotic use

The most significant modifiable risk factor for C. diff recurrence is antibiotic use. This means it’s a risk factor that can be changed.

You’re 7 to 10 times more likely to contract C. diff while taking antibiotics and in the month following antibiotic treatment.

Antibiotics change the microbiome in your intestines. In doing so, they create an environment where C. diff can grow. When antibiotics change your gut microbiome, the composition of bile acids in your colon also changes, which can promote the growth of C. diff bacteria.

Studies have found that previous use of antibiotics increases the risk of recurrent C. diff infection.

Hypervirulent strains

Since 2003, C. diff cases have become more frequent, harmful, recurring, and less responsive to treatment. This may be due to the emergence of a severe strain of C. diff known as NAP1/BI/027.

This specific strain of C. diff produces more toxins than other strains. It also produces a type of toxin that helps the C. diff bacteria grow and remain in your gut.

Additionally, this strain is very resistant to a class of antibiotics called fluoroquinolones.

People who have contracted this strain have experienced increased recurrence rates.

Gastric acid suppression

Medications to suppress gastric acid are commonly used to prevent ulcers and other health conditions related to acid. But the loss of acidity in your gut may increase your risk of contracting C. diff.

A 2017 review found that recurrent C. diff is more common in people who have used gastric acid suppressants than in those who have not.

Other risk factors

Several other risk factors may increase your risk of C. diff recurrence, including:

  • a prolonged hospital stay
  • severe underlying disease
  • decreased kidney function
  • a recent stay in a nursing home
  • a weakened immune system (due to HIV, cancer, or immunosuppressive medications)

Symptoms of C. diff recurrence are usually similar to your initial C. diff infection, including:

  • diarrhea
  • abdominal pain or tenderness
  • nausea
  • lack of appetite
  • fever

Treatment for C. diff recurrence will include a combination of antibiotics and a single intravenous infusion of a drug called bezlotuxumab to help prevent another recurrence.

The antibiotics may include:

  • vancomycin for 6 to 8 weeks
  • fidaxomicin for 10 days

According to the American College of Gastroenterology, one of the most effective treatments for recurrent C. diff is a fecal microbiota transplant (FMT).

During this procedure, stool from a healthy donor is placed in the colon of the person who is experiencing recurrent C. diff. This typically takes place during a colonoscopy.

FMT may be effective in 9 in 10 people who undergo the procedure.

New and less intrusive forms of FMT are now available. The Food and Drug Administration (FDA) has approved two types of FMT:

  • Rebyota, which can be administered in a doctor’s office
  • Vowst, which are fecal microbiota capsules taken by mouth

According to the CDC, the best way to prevent C. diff from coming back is to avoid taking unnecessary antibiotics.

When speaking with doctors and dentists, it’s important to tell them whether you’ve had a C. diff infection before. This will help them decide whether they should prescribe antibiotics.

C. diff bacteria can also be transmitted from one person to another. To help reduce the risk of transmission, wash your hands thoroughly with soap and water after using the bathroom and before eating.

The United Kingdom’s National Health Service recommends getting medical attention if you’re taking, or have recently taken, antibiotics and you experience diarrhea that:

  • is frequent
  • is bloody
  • doesn’t improve after 1 week

What happens if C. diff keeps coming back?

If C. diff keeps returning, a doctor may recommend a fecal microbiota transplant (FMT). This is usually done via a colonoscopy, during which stool from a healthy donor will be placed into your colon.

The FDA has also approved the drugs Rebyota, which can be administered rectally in a healthcare setting, and Vowst, which can be taken orally.

Once you have C. diff, do you always have it?

Some people do not, but others may become colonized by nontoxigenic C. diff, which may not cause symptoms.

Recurrence rates of C. diff are high. Once you’ve had a recurrence, your odds of experiencing another one increase.

Risk factors such as older age, antibiotic use, gastric acid suppression, and a weakened immune system may increase the likelihood of C. diff recurrence.

By avoiding unnecessary use of antibiotics and always practicing good hand hygiene, you can reduce the chances that C. diff will come back.