Evaluation of the Immune Response to Clostridium Difficile in Adults With Clostridium Difficile Infection (CDI)

Patients with an initial episode of CDI will be followed up for CDI recurrence or sustained clinical response. The subjects will be allocated into 2 groups at the study end: * Recurrence Group: Subjects who experience recurrence of CDI after clinical response to antibiotic treatment to treat the initial CDI episode. * Sustained response Group: Subjects who do not experience recurrence of CDI after clinical response to the antibiotic treatment to treat the initial CDI episode. This protocol has been amended twice to improve recruitment of subjects in the study.