I want to know that what does Islam say about Gender Reassignment Surgery. Is it prohibited in Islam? Can men or women go for this surgery and in what circumstances?
Islamic Sharī'ah has not dealt with the matter of changing sex. We can though form an opinion on the issue according to the guidance provided in the Sharī'ah, basic moral values and innate guidance.
You would agree that for a normal human being desire to change 'sex' is absent. Men and women both naturally pride themselves on being what they are; they think about the interests and rights of other members of their respective sexes: the terms 'male chauvinism' and 'feminism' though describe the undesirable extremes yet these are indicative of the spirit I am just hinting at. Thus no one normally and naturally feels aversion to having been born what he/she is.
Moreover, it should be taken as a part of divine scheme. A person should live his life being content with what Allah has decided. He has created us in a particular sex and wants us to live as he has fashioned us. Therefore, in normal circumstances, we should not tamper with the natural structure assigned by the Almighty Himself.