Efficacy and Safety of Tumor Necrosis Factor Antagonists in Treatment of Internal Fistulizing Crohn’s Disease Bouguen G, Huguet A, Amiot A, Viennot S, Cholet F, Nachury M, Flamant M, Reimund JM, Desfourneaux V, Boureille A, Siproudhis L (Clin Gastroenterol Hepatol. 2020 Mar;18(3):628-636 – PMID: 31128337) https://pubmed.ncbi.nlm.nih.gov/31128337/