If initial results from a digital rectal exam (DRE) or prostate-specific antigen (PSA) test suggest the possibility of prostate cancer, a provider may request a urinalysis to help rule out a bacterial infection. A urinalysis can reveal abnormalities such as blood or nitrates in the urine. Traces of blood in the urine may indicate that a kidney stone or infection is present. The sample might reveal bacteria or infection-fighting white blood cells, which would indicate an infection. Nitrates in the urine can also indicate the presence of a bacterial infection.