For 3-month postoperative copeptin levels to be used as a robust diagnostic for permanent CDI, a few caveats should be addressed in the prospective study such as the relationship between immediate postoperative copeptin levels and 3-months postoperative copeptin levels, the effect of desmopressin intake on serum copeptin levels, and the international standardized copeptin measuring protocol. The gene discussed is AVP; the disease is clostridium difficile infection.