The aim of the project was to optimalize the process in severe peritonitis which is generally inflicted with high mortality and morbidity with long term costly therapy. Therapy of severe intraabdominal infection consist of treatment of the infection site and following closure of the abdominal cavity with possibility of re-laparotomy and in treatment of complications when needed; or closure introduction of laparostomy with intention to control complications prevention however with risk of tertiary peritonitis. Modern process is laparostomy with active suction (VAC) method which reduces the risk of tertiary peritonitis. It efficacy is however approved especially in therapy of complications. Based on the investigators experiences the investigators use this method even in case of primary treatment of severe peritonitis which led to protocol processing (VAC in case of primary closure of the abdominal cavity; VAC exchange according to scoring system; secondary closure of the abdominal cavity or early coverage with collagen mesh). The aim of this project is to prove reduced mortality, morbidity and hospitalization length (cost reduction) in prospective randomized study in patients treated due to severe peritonitis using VAC method in comparison to classical approach (primary closure of the abdominal cavity; secondary solution of complications).