The presence of bacteriuria 48-72 hours after cystoscopy has been correlated with the sex and previous history of the patient, and with the use of chlorhexidine 1/5,000 and water as alternative irrigant solutions. The infection rate was higher in women than in men. Chlorhexidine in the irrigant solution protected against postoperative bacteriuria in patients who did not have a history of previous urinary infection, but did not do so where there was such history.