OBJECTIVE:To investigate the prevalence of asymptomatic bacteriuria (ABU) and urinary tract infection (UTI), and the local and systemic inflammatory response, in patients with ileal neobladder.PATIENTS AND METHODS:The study included 40 patients who had a radical cystectomy and ileal neobladder. Two urine samples, one for chemical and physical analysis, and cytofluorimetry, and one for urine culture, were collected every 3 months for 9 months after surgery.RESULTS:Of 119 urine cultures, 69 (57%) were positive for bacteria. Only nine of the 40 patients had no bacteriuria on urine culture. Escherichia coli strains were cultured from eight of 10 patients with persistently positive urine. The incidence of bacteriuria was different according to gender. There was a high concentration of leukocytes (0-6 microL) in 118 of 119 samples. The mean concentration of leukocytes in sterile urine culture was 1181/microL, while in patients with ABU the mean was 491 (P < 0.05).CONCLUSION:A positive urine culture is a very common finding in patients with an orthotopic bladder. The most interesting results was the absence of elevated inflammatory indices and/or symptoms, even in those patients with high levels of bacteriuria. Probably this is due to the completely different inflammatory response of ileal mucosa against bacteria than has bladder mucosa. Indeed, the leukocyte concentration detected in urinary sediment was inversely association with bacterial growth in urine cultures. These findings suggest a redefinition of ABU and UTI in patients with an orthotopic neobladder.