In the under 3 year old age group, urinary tract infection is more common in uncircumcised boys.

In an article published in CMAJ, the authors report studying 404 boys under 3 years old. All these children presented to a large emergency department with symptoms suggestive of urinary tract infection and had a catheter urine specimen sent for microbiological studies. Only 393 cultures were available and the 11 boys without available results were excluded. The majority (90%) of the remaining 393 children were circumcised. 80 had proven urinary infection, of which 30% of uncircumcised boys had positive cultures compared to only 4.8% of circumcised boys. This was a significant difference with an odds ratio of 0.07. The authors concluded that the risk for urinary tract infection is higher in uncircumcised vs circumcised boys younger than 3 years. They went on to report that in uncircumcised boys 3 years and younger, the odds of having a urinary tract infection is not affected by the visibility of the meatus.