 The aim in this study during the study period is not to change the existing management of AP. The existing guidelines for treatment of severe AP patients do not include enzyme supplementation therapy. However, if the patients have low fecal elastase-1 levels indicating pancreatic exocrine insufficiency after the follow-up period of 12 months, they will be informed about the enzyme supplementation therapy. And if the patients are willing to start the therapy, it can be administrated. 