Patient with severe peritonitis will be enrolled in study according to Mannheim Peritonitis Index (MPI) - more than 20-25 according to sex; APACHE II more than 10. Expected sample size is total of 50 patients (25 treated using VAC method) versus 25 in control group). Screening will include all patients designer fulfilling SIRS criteria prior abdominal approach and/or displaying symptoms of peritonitis. If patient fulfills these criteria and agrees with inclusion in study, his/her ID is entered in the electronic database which generates inclusion in one out of two groups according randomization scheme - surgery termination using VAC method or primary suture. Excluded patients: young patients younger than 18 years; mental state of patients which does not enable proper information and signature of informed consent form (see bellow) with inclusion in study; further patients who cannot be assume to live longer than 48 hours after surgery (APACHE II, Karnofski, SOFA).