First, circumcision (male) and clitorectomy (female) (I won't call it female mutilation although that's what I think it is) are for different purposes. Circumcision does not impair a male's ability to derive sexual enjoyment and fulfillment or have an orgasm.

Secondly, circumcision is usually performed (except for medical reasons or religious conversion) in the first few days of life. There is some evidence that the nervous system of newborn babies is wired differently with lower pain thresholds (or else how would anyone survive the trip down an 6-8" birth canal?)

Thirdly, I don't know of any religious canon that commands a clitorectory although circumcision is part of the covenant Y*hw*h/Allah made with Abraham.

It has been known for a long time that women of circumcised partners have a low incidence of cervical cancer. The studies concerning HIV transmission rates are more recent.