Hi Dr. My son got UTI in Nov and after 1 course of Zinacef (3.6cc/day and 9 days in a roll). Since I don't want him undergo VCUG, we keep on checking his urine every month. Last week, we found there is no increase in WBC, but small amount of E-Coli found in the urine. We take him for re-check, since the lab suspect urine was contaminated, but E-coli still found in second trial. Pls advise is it normal if small amount e-coli found in urine and will it cause my son hv UTI later? Thks