A urine culture requires as sterile a specimen as possible; that is, one that is not contaminated by the bacteria that normally inhabit the area around the urinary meatus (the opening through which the urine leaves the body). (fcrsa.org)
Inflammation of the meatus (the opening of the penis) may occur after circumcision and can possibly lead to scarring. (pregnancy-baby.com)
This is due to diaper rash and chaffing because in circumcised boys, the meatus is more exposed. (pregnancy-baby.com)