Age greater than 65
Prior C. difficile infection
Recent antibiotics within last 3 months
Immunosuppression (e.g. chemotherapy in last 3 months, solid organ transplantation, HIV, systemic corticosteroid use)
Gastric acid suppression therapy (e.g. proton pump inhibitors, H2-receptor antagonists)
Bowel disease and/or bowel surgery
Prolonged or recent hospitalization within last 3 months
