What is your approach to secondary prophylaxis for C difficile infection during concomitant antibiotic use in a patient with a history of C difficile infection?

We have been restricting secondary prophylaxis to those patients with severe protein malnutrition, receiving immunosuppressive chemotherapy, generally at the extremes of age who require unavoidable systemic antibiotics that cannot be withdrawn. Based on the 2024 paper by Ronza Najjar-Debbiny et al., PMID 38719086, we have been treating with a combination of fidaxomicin and Vowst - originally with FMT from Open Biome but that has become virtually impossible to obtain. This regimen is continued for the duration of the systemic antibiotic plus an arbitrary 3-5 days. Fidaxomicin is bid, and Vowst is bid, each separated by 6 hours. Major issue - getting insurance payment for Vowst or “begging/borrowing/stealing products from the sponsor. (Big sh...