C. diff Infection in Northern Virginia

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C. diff infection is a bacterial infection of the colon that causes diarrhea and inflammation, and most cases begin while a person is taking antibiotics or in the weeks just after finishing them. The germ's full name is Clostridioides difficile, and it was once called Clostridium difficile, which is why you may see either name on a lab report. What makes a C. diff infection frustrating is that it can come back after successful treatment. This guide explains why antibiotics set the stage for it, how it is diagnosed, how it is treated today, why it recurs, and what can be done to break that cycle.

This article is general education, not medical advice. If you develop diarrhea during or after a course of antibiotics, contact a healthcare professional so it can be evaluated.

What a C. diff infection is

The Centers for Disease Control and Prevention (CDC) describes C. diff as a germ that causes diarrhea and inflammation of the colon, called colitis, and notes that the infection can be life-threatening. The CDC estimates that C. diff causes almost half a million infections in the United States each year. The bacterium releases toxins that damage the lining of the colon, and those toxins are what produce the symptoms.

C. diff survives outside the body as a spore, an inactive form with a protective coating. According to the CDC, these spores can live for months or years on surfaces and in soil, and they become active again after being swallowed and reaching the intestines. The CDC also notes that finding C. diff in a home is not unusual even when no one in the home has been sick, and that most healthy people do not become infected even if spores reach their intestines. Something has to tip the balance first, and that something is usually an antibiotic.

Why a C. diff infection follows antibiotics

Your gut holds a large community of helpful bacteria, often called the microbiome. The CDC explains that a healthy microbiome helps break down food, supports the body's natural defenses, and protects against infections. Antibiotics kill the bacteria causing an infection, but they also kill many of those helpful bacteria. With fewer protective bacteria in the way, C. diff has room to grow and release its toxins.

The size of that effect is striking. The CDC reports that people are up to 10 times more likely to get a C. diff infection while taking an antibiotic and during the month after finishing it, and that longer courses may double the risk. The CDC also notes that the effects of antibiotics on the gut microbiome can last for several months, so the window of vulnerability does not close the day the last pill is taken.

Any antibiotic can raise the risk. The CDC's guidance for clinicians singles out fluoroquinolones, third- and fourth-generation cephalosporins, clindamycin, and carbapenems as the antibiotic classes most associated with it. That list is useful background for a conversation with your physicians, not a reason to refuse an antibiotic you need.

Who is most at risk for C. diff infection

Anyone can develop a C. diff infection, including people with none of the usual risk factors. The CDC lists these as the main ones:

• Recent antibiotic use, the strongest and most common factor
• Age 65 or older
• A recent stay in a hospital or nursing home, which the CDC's clinician guidance describes as within about the last three months
• A weakened immune system, such as during cancer treatment or after an organ transplant
• A previous C. diff infection or known exposure to the germ

People with inflammatory bowel disease deserve a specific mention. A 2026 clinical practice update from the American Gastroenterological Association (AGA) on C. diff in inflammatory bowel disease notes that people with Crohn's disease or ulcerative colitis face a greater risk of C. diff, more severe infections, and a higher chance of recurrence. It advises that C. diff be ruled out whenever someone with inflammatory bowel disease has new or worsening diarrhea, especially when the colon is involved. If you live with either condition, our guide to Crohn's disease and ulcerative colitis explains why a flare and an infection can look alike.

Acid-reducing medications are part of the conversation as well. The CDC describes proton pump inhibitors (PPIs) as hypothesized to increase the risk of C. diff infection. The 2026 AGA update on C. diff in adults advises that PPI use be reviewed during treatment and recurrence prevention, while also stating that discontinuation is not necessary when there is a legitimate reason to take one. Our guide to GERD and acid reflux covers how those medications fit into long-term care.

Symptoms of a C. diff infection

The CDC lists the main symptoms as diarrhea, fever, stomach tenderness or pain, loss of appetite, and nausea. Diarrhea is the defining feature, and the CDC's guidance for clinicians uses three or more loose stools in 24 hours as the point at which testing should be considered in a healthcare setting.

It is worth keeping perspective, because diarrhea during a course of antibiotics is common and usually has nothing to do with C. diff. The CDC notes that C. diff accounts for roughly 15 to 25 percent of antibiotic-associated diarrhea. The rest is typically milder and settles on its own. That is why the CDC's advice is simple: if you develop diarrhea while taking an antibiotic or after finishing one, contact a healthcare professional and be evaluated rather than assume either way.

When C. diff infection needs urgent care

Most C. diff infections are treated at home. The CDC lists dehydration and colitis as the common complications, and toxic megacolon, sepsis, and death as rare ones. The 2026 AGA update describes a severe infection in hospitalized patients as one with a markedly elevated white blood cell count or a sharp rise in creatinine, a kidney measure, and a fulminant infection as one that adds shock, a stalled bowel, or a severely enlarged colon.

Seek emergency care for severe or worsening abdominal pain, a swollen or distended belly, high fever, confusion, or signs of dehydration such as dizziness or very little urine. These call for same-day evaluation at an emergency department, not an office appointment.

How a C. diff infection is diagnosed

A C. diff infection is diagnosed with a stool test, but the test alone is not the diagnosis. The 2026 AGA update describes it as a clinical diagnosis that requires compatible symptoms, typically new diarrhea after antibiotics, together with supportive laboratory results. It prefers multistep testing for accuracy, and it advises treating people whose tests disagree when clinical suspicion is high.

The reason for that care is a difference the CDC draws between colonization and infection. Colonization with C. diff is more common than infection. A colonized person carries the germ, may test positive, and has no disease from it. That is why the CDC recommends testing only unformed stool, why clinicians rule out other causes such as laxatives first, and why a positive test in someone without diarrhea does not mean treatment is needed.

The same logic applies after treatment. The CDC and the 2026 AGA update both advise against routine retesting to confirm the infection is gone once symptoms have resolved. The CDC notes that tests may stay positive for six weeks or longer, and that a positive result would only show the germ is still present, not whether you are likely to get sick again. Stool testing is repeated only if diarrhea persists or returns.

Treatment for C. diff infection

Treatment starts with the antibiotic that caused the problem. The CDC notes that if you are taking an antibiotic for another infection, a healthcare professional may stop it or switch to a different one when it is safe to do so. That decision belongs to the prescribing physician.

Fidaxomicin and vancomycin

The infection itself is treated with specific antibiotics that act inside the gut. The CDC names oral vancomycin and fidaxomicin, given for at least 10 days. Current guidance leans toward fidaxomicin. The 2026 AGA update favors it as first-line therapy for infections that are not fulminant, citing lower recurrence rates and a narrower spectrum, while stating that vancomycin is also acceptable for practical reasons. The 2021 focused update from the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America reached the same conclusion, finding that fidaxomicin produced a more lasting response than standard vancomycin four weeks after treatment.

Cost is the practical limit. The 2021 update acknowledges that fidaxomicin's price may be prohibitive without adequate insurance coverage, notes that patient-assistance programs exist, and states that vancomycin remains an acceptable alternative. Which drug a person receives often depends on coverage as much as on preference, and both are recognized treatments.

What has changed in C. diff treatment

Two older approaches have fallen away. The 2026 AGA update advises that metronidazole should not be used outside of fulminant disease. It also advises against cholestyramine and other bile acid binders, either alone or alongside vancomycin or fidaxomicin, though it notes that psyllium fiber can help firm stools after recovery.

The other change is bezlotoxumab, an infused antibody that was once used alongside antibiotics to lower the chance of recurrence. It still appears in the 2021 guideline and in many older articles online, but it is no longer an option in the United States. The American Society of Health-System Pharmacists reports that Merck, its only supplier, discontinued it in January 2025.

Why C. diff infection comes back

Recurrence is the defining challenge of this infection. The CDC reports that about 1 in 9 people who get a C. diff infection will get it again within 2 to 8 weeks. That can be a relapse of the original infection or a new infection from another exposure. The 2021 focused update notes that the risk of a further recurrence rises with each episode, and lists age 65 or older, a weakened immune system, and a severe first infection among the factors that may raise recurrence risk.

The underlying reason is the same one that allowed the first infection. The treatment antibiotics clear the active infection, but they do not restore the protective bacteria that were lost. Until the microbiome recovers, spores that survived treatment or that are picked up again can take hold. Breaking the cycle means treating the recurrence and, for many people, helping the gut rebuild its defenses.

Treating a first recurrence

The 2026 AGA update advises that a first recurrence within 8 weeks of finishing treatment be treated with either a tapering course of vancomycin or fidaxomicin. It also advises that treatment include an assessment of recurrence risk and a consideration of therapy to restore the gut microbiome.

Microbiome restoration and fecal microbiota transplant

Fecal microbiota transplant, often called FMT, transfers stool-derived bacteria from a carefully screened healthy donor into the colon of a person with recurrent infection, so the missing protective bacteria can take hold again. The CDC describes it as an innovative treatment that has shown promising results for people with reinfections.

Two products are now approved by the U.S. Food and Drug Administration (FDA) for preventing recurrence in adults after antibiotic treatment for recurrent infection:

• Rebyota (fecal microbiota, live-jslm), approved in November 2022, is given as a single dose into the rectum by a healthcare professional.
• Vowst (fecal microbiota spores, live-brpk), approved in April 2023, is taken by mouth as four capsules once a day for three days. The FDA reports that in its clinical trial, recurrence through 8 weeks was 12.4 percent with Vowst compared with 39.8 percent with placebo.

Conventional FMT, often delivered during a colonoscopy, remains an option as well. On timing, the 2026 AGA update advises that these microbiota-based therapies be offered after treatment of a second recurrence, meaning a third episode, and that they may be considered earlier for people at high risk of further recurrence or whose first infection was especially severe or hard to treat. The AGA's 2024 guideline on these therapies adds an important limit: it suggests conventional FMT for mildly or moderately immunocompromised adults but suggests against microbiota-based therapies in severely immunocompromised adults. Because these products are made from human donor stool, the FDA notes that they may carry a risk of transmitting infectious agents despite donor screening, which is part of the benefit and risk discussion.

For people who cannot receive a microbiota-based therapy, or who have had several recurrences despite it, the 2026 AGA update notes that a prolonged, low-dose suppressive course of vancomycin may be considered. A gastroenterologist can help weigh these options against your health history.

Preventing a C. diff infection at home

Because the spores are hardy, the CDC emphasizes practical hygiene. Hand sanitizer does not kill C. diff, so washing with soap and water matters. The CDC's advice for households includes:

• Wash your hands with soap and water every time you use the bathroom and before you eat, and ask caregivers to do the same.
• Use a separate bathroom during the illness if you can, or clean commonly touched bathroom surfaces before others use it.
• Clean frequently touched items such as doorknobs, electronics, refrigerator handles, toilet seats, and flush handles, using a product on the Environmental Protection Agency's list of disinfectants effective against C. diff.
• Wash bedding, towels, and clothing in the hottest water the fabric allows, using chlorine bleach where it is safe for the items.

The 2026 AGA update adds reassurance worth repeating: spread to healthy family members is uncommon. It also advises against probiotics to prevent a first or recurring infection, and recommends a healthy diet with a variety of fruits and vegetables rich in fiber to support the gut microbiome. Most importantly, both the CDC and the AGA advise that anyone who has had C. diff avoid unnecessary antibiotics and tell every clinician who prescribes them, including your dentist, about the history.

If you are sorting through other reasons for ongoing loose stools, our guide to chronic diarrhea in Northern Virginia covers the broader picture, and our guide to microscopic colitis explains another cause of watery diarrhea that stool tests cannot detect. Our page on probiotics for digestive health explains how the 2026 advice on probiotics compares with the AGA's older 2020 probiotics guideline. General patient information is available from the CDC, and the American Gastroenterological Association publishes its recommendations on microbiota-based therapies.

Care for C. diff infection in Northern Virginia with GC of NoVA

Gastroenterology Center of Northern Virginia sees patients across Arlington, Annandale, and the surrounding communities who are dealing with a C. diff infection, especially one that has returned after treatment. Our physicians can review your antibiotic and medication history, coordinate with the doctors who prescribe for you, talk through treatment and recurrence prevention, and evaluate whether ongoing symptoms point to C. diff or to something else, such as inflammatory bowel disease or microscopic colitis. We see patients at our Arlington office, next to VHC Health, and our Annandale office, in the Woodburn Medical complex. If you are unsure whether your symptoms call for a specialist, our guide on when to see a gastroenterologist may help, and our guide to your first gastroenterologist visit explains what to bring.

To schedule an evaluation, contact our Arlington office at (703) 522-7476 or our Annandale office at (703) 560-6106, or learn more at gcofnova.com. If you have severe abdominal pain, a swollen belly, or signs of dehydration, go to the nearest emergency department.

This article is for general education and is not medical advice. Talk with a qualified gastroenterologist about your symptoms, diagnosis, and treatment options.