First of all this topic makes me nauseous.... the thoughts of having that entire area removed, the clitoris, labia, etc, without any anaesthetic is a terrifying thought for me... I can't even imagine how bad that would be, especially since that practice is generally performed on 11-14 y/o girls (and sometimes much younger!), I don't think that is something I could handle now let alone at that age. They do not use any kind of disinfectant and do not perform this in sanitary conditions. Also, the cutting instrument is not necessarily a sharp razor blade, quite often it is a piece of broken glass or a tin lid, or scissors, the girls legs are held open, and everything is cut away. It is not uncommon for girls to die as a result of this operation and if they don't die when it is done, then there are sever complications when giving birth to children, and labour often takes days because of the scar tissue that builds up as a result of the procedure, and quite often the skin/scar tissue has to be cut to allow for childbirth. Also this is not a religious practice; it is not endorsed by ANY religion (that i know of, if am wrong let me know).
btw, here is an interesting article on the subject >>>
http://www.amnesty.org/ailib/intcam/femgen/fgm1.htm#a2