ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections. Kelly CR, Fischer M, Allegretti JR, LaPlante K, Stewart DB, Limketkai BN, Stollman NH. Am J Gastroenterol. 2021 Jun 1;116(6):1124-1147. doi: 10.14309/ajg.0000000000001278. PMID: 34003176.