Diagnosing and Managing C difficile Infection in Patients With IBD

Diagnosing Clostridioides difficile infection (CDI) in patients with inflammatory bowel disease (IBD) “is one of the trickiest and most nuanced parts of caring for these patients,” Jessica Allegretti, MD, explained at the Advances in Inflammatory Bowel Disease (AIBD) virtual regional meeting on July 25.

Dr Allegretti is codirector of the Crohn’s and Colitis Center at the Brigham and Women’s Hospital and assistant professor of medicine at Harvard Medical School in Boston, Massachusetts.

As the most common healthcare-related infection in the United States, CDI has decreased in the population as a whole by as much as 26%, she reported. However, the incidence of CDI among patients with IBD—and particular in those with ulcerative colitis (UC)—increased significantly between 2000 and 2005. The prevalence of CDI in patients with IBD is between 2.5- and 8-fold greater than in patients without IBD, and patients with IBD and CDI have a 4.5-fold higher risk of recurrent infection, Dr Allegretti explained.

The sequalae of CDI in patients with IBD can include serious complications, from loss of response to therapeutic agents to colectomy, additional recurrences of CDI, and higher mortality. Therefore, identifying CDI quickly is very important. However, the symptoms of CDI closely overlap the symptoms of an IBD flare—diarrhea, abdominal pain, and fever—making the diagnosis less obvious.

These factors, taken together, led Dr Allegretti to emphasize that “all patients with IBD with worsening disease should be tested for CDI every time.” Patients with IBD who have CDI often do not fit the profile of the typical CDI patient, she said. These patients may be younger and may develop CDI while outside of the hospital. Also, she stated, “Colonization without infection is common.”

She also cautioned that “not all tests are created equal.” The European Society of Clinical Microbiology and Infectious Diseases guidelines clearly state that “no single commercial test can be used as a stand-alone.” Dr Allegretti advised using a 2-step approach, beginning with a highly sensitive test such as GDH or PRC, and if that test is positive for CDI, go on to a very specific test, such as EIA, which has a high positive predictive value for toxins produced by C diff.

She then went on to discuss the challenges of treating CDI in patients with IBD, as well as treatment options.

When treating patients with IBD for CDI, she said, “I cannot stress enough that you must treat your patients as if they have severe C diff—even an outpatient doing well.” IBD can be considered a marker of CDI severity in and of itself, she emphasized.

Further complicating the treatment landscape is the fact that the immunosuppressive drugs patients with IBD often take “may worsen the underlying C diff infection but are required to manage a flare caused by CDI,” Dr Allegretti said. “You have to address both diseases if you stop the immunosuppressives; the IBD is likely to get worse.” Data is mixed on the use of antibiotics alone vs adding immunosuppressives to antibiotics, she noted, but the current solution is to use both therapies.

Patients with IBD are also at higher risk of recurrent CDI, she noted. About 20% to 25% of patients with IBD who contract CDI will have a recurrent episode. “Each recurrence makes the next more likely,” she explained. “Age, antibiotic exposure, more virulent strains of C diff, and IBD with colitis are all risk factors for recurrent infection.”

“The big take home point on this issue is, do something different,” Dr Allegretti stressed. “Switch antibiotics, use a prolonged taper with vancomycin.” A new treatment, bezlotoxumab, is intended not to treat recurrent CDI but to prevent further recurrence. But for additional recurrence of CDI in patients with IBD, she said, “we’re really talking about fecal microbiota transplantation [FMT].”

She explained that while FMT is not approved the US Food and Drug Administration, the agency exercises its enforcement discretion to permit the use of FMT in recurrent or refractory CDI. Dr Allegretti explained that FMT has been shown to be very effective in treating CDI and preventing recurrent infection, with success rates of more than 90% in some studies.

The takeaway, Dr Allegretti said, is “always test for CDI in patients with IBD who present for a flare of their disease, and when the patient has multiple recurrences, FMT is safe and effective and should be offered.”


—Rebecca Mashaw



Allegretti, JR. Clostridioides difficile infection in inflammatory bowel disease: diagnosis and management. Talk presented at: Advances in Inflammatory Bowel Disease 2020 regional meeting; July 25, 2020; virtual.