The ascending gas and fluid stream method was applied in 12 patients with repeated purulent diffuse peritonitis. The number of leukocytes was determined in lavage fluid in order to estimate the efficacy of the method. Dynamics of general laboratory and clinical indices was compared with dynamics of leukocytes quan- tity. The research showed the adequacy of investigation results of lavage fluid to the course of inflammatory process in the abdominal cavity. The study presented an application possibility of given test for regulation usage correction of the ascending gas- fluid stream method.