Diagnosis and Management of C. difficile Infection (CDI) in Patients with Inflammatory Bowel Disease

Paul Feuerstadt, MD: Now, you mentioned earlier a little bit about colonization. Bincy, can you walk us through what colonization is, in general? Then, when do you test for C. [Clostridioides] difficile in a patient with inflammatory bowel disease, and do you have a test of choice?

Bincy Abraham, MD, MS: Colonization, interestingly, in our IBD patients can vary. I've seen it significantly more so in our patients that have had recurrent C. diff, refractory C. diff infections, along with patients that have still moderate to more severe inflammatory bowel disease. We think it's related to the alterations of microbiome, where the patients with the active disease are unable to get their normal flora back and to stay in place, essentially. The C. diff continues to recur or starts to become activated from the spore to active form. Those cases can be very challenging to treat, in part, and I'm sure we'll talk about this in the future, about getting the C. diff under control (it) involves getting their inflammatory bowel disease under control to prevent those recurrences and get rid of that colonization, if possible, for these patients. Now, as far as testing an IBD patient for C. difficile infection, it can be challenging. The main challenge is because patients with IBD, if they end up getting C. diff, it's hard to differentiate if it's really C. diff infection, or is it really an IBD flare? In our general population, if patients end up getting diarrhea or pain, it's easy because you know something is different for them. They need to be evaluated and tested. The IBD patient, when they're getting diarrhea, you can't really say it's necessarily from C. diff infection. It could be an exacerbation of their inflammatory bowel disease. In my general practice, whenever a patient that has IBD starts telling me that they are having a flare, I often check for C. difficile infection along with their assessment of their IBD. I think it varies. Knowing that the burden of disease is high, we know that there's an increased risk of C. diff infection in the IBD patient population, I truly believe it's very important to test when there's a true clinical suspicion for them. This is especially true when your patients have been in remission of their IBD then all of a sudden develop acute onset of symptoms, sometimes could be similar to their IBD flare, but oftentimes, patients will also tell us that this flare seems a little bit different to their typical Crohn's disease flare or their ulcerative colitis flare, and that's when my radar goes up to think, "Could this be something different?" It's a C. diff infection or another type of bacterial infection, which our patients with IBD are also at increased risk for as well. That can include E. coli and salmonella, and other things, not just C. difficile. Again, going back to when to test, whenever there's a clinical suspicion when their disease symptoms have changed, when they go from remission to an actual flare, which is when we typically test for a C. diff infection. It's important because the sooner we test them the sooner we can get them treated. It's always better for their disease process because our IBD patients can deteriorate quite quickly and end up being hospitalized during worsened severity of their overall gut health itself.

Paul Feuerstadt, MD: Excellent. Well, I think you covered really the general idea, multiple pearls came out of that little piece, but really, any time a patient presents with a potential inflammatory bowel disease flare, we can think about testing them for C. difficile. Also thinking about generating that differential diagnosis that we spoke about before. As we shift gears, and we're going to talk in much greater detail about treatment of C. difficile, can you walk us through what your treatment algorithm is for a patient with inflammatory bowel disease that is diagnosed definitively with C. difficile?

Bincy Abraham, MD, MS: Key steps to take include having a strong clinical suspicion early on, test them early on, and then treat them early on, along with assessing their disease activity for inflammation. What you want to do is, once you have confirmed the diagnosis, I'm always testing for the toxin because again these patients could have been colonized, they've had disease previously, or a C. diff infection previously. I always want to check for the toxin to see if that's what's activating their symptoms. So, if they're toxin positive, then I go ahead and start treating them aggressively. Our guidelines have switched, we no longer even mention metronidazole in our IBD patient population, we've been switching over to initiating therapy with at minimum vancomycin, and now with newer guidelines, it's just starting them with fidaxomicin. Typically, either of those is what we start with, and in our IBD patients, which should be your initial treatment. We know that those medications provide better efficacy of treatment and reduce the risk of recurrence as well. The other main aspect of treating C. diff infection in IBD patients, you can just go by treating the C. diff infection alone. Very often, their IBD is also in a flare, and you need to be aggressive in treating their inflammatory bowel disease. What often happens is that physicians or hospitalists may, especially these patients in the hospital with the severe infection, is often our IBD patients are on immunosuppressive therapy, they think, "Well, there's an infection going on, we've got to stop or hold their biologics or small molecules," and that's actually the incorrect way to treat them. You must be aggressive on both fronts, treating the C. diff and treating their IBD. Often, we're starting new biologics, or increasing their dosing or frequency to get their IBD under control because if we don't get their IBD under control, you can treat their C. diff initially, but most often they will recur, or it will take much longer to get rid of the C. difficile infection in those patients. That's a very key point, in managing C. diff infection in IBD patients: You have to treat both aspects aggressively, and early on.

Paul Feuerstadt, MD: Excellent, and going with the flow on these patients of course, also. If you're treating the C. difficile, and you're keeping their other treatments stable, and they're not getting better, that might be a circumstance to intensify some of the other medications. Really thinking our way through this and assessing in real time because these patients with inflammatory bowel disease, and C. diff, are frankly, complicated, and we need to best understand what you just listed for all of us.

Transcript edited for clarity