Clostridium-difficile-associated diarrhea (CDAD) is the most common cause of hospital-acquired diarrhea. Although initial response rates to specific antibiotic therapy exceed 90 percent, 10-30 percent of patients experience disease recurrence. Risk factors influence CDAD recurrence are not yet fully understood. A research group in Korea investigated the risk factors for CDAD recurrence. Advanced age, serum albumin levels less than 2.5g/dL and use of PPIs were found to be significant risk factors for CDAD recurrence.