Recurrent acute pancreatitis (RAP) was defined as two or more occurrences of acute pancreatitis, which was associated with higher percentages of morbidities and mortalities, lower patients' life quality and increased health-care costs. Current interventions, including cholecystectomy and abstain from drinking were reported to be effective methods for preventing the recurrences of biliary and alcoholic etiologies, respectively. However, there were no effective preventions for other etiologies, such as idiopathic etiologies. Non-steroid anti-inflammatory drugs (NSAIDs), including indomethacin, diclofenac and aspirin could inhibiting the inflammatory cascade of pancreatitis. In this study, we aimed at exploring the effects of 100mg aspirin on reducing the occurrences of recurrent acute pancreatitis.