Objective: Staged abdominal lavage is routinely performed in the management of severe forms of diffuse peritonitis. In the present study the question about fluid absorption in the treatment course of severe intraabdominal infection should be answered. Additionally the clinical application of cytokine monitoring was examined during staged lavage. Methods: Nineteen patients with severe intraabdominal infections have been investigated during 75 staged lavages. Serum and peritoneal Il-6, Il-8, Il-10 and TNF were measured before surgical intervention, after one, three, six and 24 hours. Additionally cardiorespiratory parameters, total amount of irrigant fluid, serum Na+, K+, Cl-, lactate, total protein concentrations and blood gas analysis have been recorded during the perioperative course. Results: 1. There were no signs for significant fluid absorption during performance of staged lavage with total amounts of approximately 3000-5000ml normal saline. 2. There were no relevant changes of hemodynamic parameters during the perioperative period of staged lavage with a sufficient circulatory treatment. 3. There was a temporary increase of the serum cytokines Il-6 and Il-8 as an indicator of an enhanced inflammatory host response. 4. There was no correlation between cytokine levels of serum and intraabdominal cavity. Conclusions: There is no additional danger in the treatment of severe peritonitis with staged lavage. Cytokine measurements do not offer a new diagnostic tool in the abdominal lavage peritonitis treatment.