Urodynamic morbidity and dysuria prophylaxis. A group of 324 patients received prophylactic treatment with either sodium bicarbonate, potassium citrate or a glucose placebo following urodynamic studies. Urine was screened for infection both before and after testing and the incidence of dysuria assessed by postal questionnaire; 63% of patients experienced some degree of dysuria and this was severe and prolonged in 6.3%, the majority of whom were male. Neither sodium bicarbonate nor potassium citrate was any more effective in preventing dysuria than placebo. The presence of severe prolonged dysuria was not associated with a urinary tract infection or with any particular urodynamic diagnosis. 