Circumcision is not only done on men, but also performed on women. Circumcision for men is to cut all qulfah (skin) that covers the ends of dzakar, while for women is to cut the skin of the prominent (and above) farjinya only.
Circumcision is a Sunnah of Prophet Ibrahim. The Prophet sallallaahu alaihi wa Salam said, which means: "Khalilur Rahman Ibrahim berkhitan after the age of 80 years and he berkhitan with an ax." (HR: Al-Bukhari)
Berkhitan allowed after baligh. Ibn Abbas was asked, which means: "Who are you when Rasululloh age sallallaahu alaihi wa Salam died?" Ibnu Abas said: "I was at that time was already circumcised, and the people (those days) did not circumcise male until he baligh." (HR: Al-Bukhari)
Among the functions for male circumcision is to remove the dirt and unclean nest. Whereas for women are (among others) to stabilize syahwatnya stimulation. If circumcised too deep could make him have no desire at all, on the contrary, if the skin is a prominent upward vaginannya (clitoris) is cut can be dangerous, because if rubbed or touched something he quickly aroused. So Rasululloh sallallaahu alaihi wa Salam said to the carpenters circumcision woman (Umm A'Thiyyah), which means: "Do you cut out, because (do not cut out) was more beneficial for women and more unpopular husband." (Reported by: Abu Dawud)
Regarding circumcision for women is indeed not known by most of our society, but hopefully through this information, we begin to practice it and for the Muslim with the medical profession began to study or learn it so help Muslims in performing female circumcision, so do not let Muslim women who circumcise a baligh are the men.
A concern when not in circumcision for women is going to be one of the driving causes him to become a lesbian. Thus Islam ordered that stabilize syahwatnya by circumcision.
(Source Reference: Shohih Al-Bukhari, Sunan Abu Dawud; Ahkamun Nisa '),