S1913 Comparing the Recurrence Rate of Clostridioides difficile Infection (CDI) in Patients With Inflammatory Bowel Disease After Low, Medium, and High Dose Oral Vancomycin After the First Episode of CDI

Introduction: Oral vancomycin (OV) is commonly used for an initial Clostridioides difficile infection (CDI) episode in patients (pts) with inflammatory bowel disease (IBD). There are no guidelines to recommend what dose of OV should be used to prevent recurrent CDI (rCDI). In this study, we sought to evaluate the risk of rCDI in IBD pts treated with low (125 mg), medium (250 mg), and high (500 mg) dose OV and to examine the risk factors associated with rCDI in this population. Methods: A single-center retrospective study was performed on pts diagnosed with IBD who developed CDI between 2014 and 2024. Recurrence of CDI was defined as initial symptom improvement followed by symptom recurrence and positive stool toxin testing within 8 weeks of completing initial antibiotic therapy. The following data were obtained: baseline demographics, details of IBD history including medication use, treatment of first CDI including dose of OV (low = 125 mg, medium = 250 mg, and high = 500 mg), and rCDI. Categorical variables were analyzed using Pearson’s chi-squared or Fisher’s exact test. Continuous variables were compared with t-tests. An overall logistic regression model for rCDI was fit to produce adjusted odds ratios for predictors. Results: 273 IBD pts (CD, n = 123 pts [45.1%]; UC, n = 150 pts [54.9%]) with a CDI diagnosis treated with OV, were identified. Of these pts, 38 (13.9%) had a diagnosis of rCDI. Even though the rates of rCDI were not statistically significant in UC pts vs CD patients, there was a trend towards slightly higher rCDI in the UC cohort (14.6% vs 13%, P = 0.83). 85% of pts received 125 mg OV, 9.5% 250 mg and 4.4% 500 mg (1.1% pts had missing data). Biologic therapy decreased risk for rCDI (aOR 0.38, CI 0.153-0.869, P = 0.027). Compared to low dose OV, there was no increased odds of rCDI in the 250 mg group (P = 0.23) or 500 mg group (P = 0.91). Gender (P = 0.95), race (P = 0.74), IBD subtype (P = 0.56) did not increase risk of rCDI. Conclusion: There was no significant difference between low, medium, or high dose OV and the risk of rCDI. The use of biologics decreased the risk of rCDI. A future prospective study with a larger sample size is necessary to confirm these findings and help guide the management of IBD patients with CDI. Although recent guidelines recommend fidaxomicin as the preferred first-line treatment for CDI, OV remains a valid option.