Original sentence: The most prevalent form of genital alteration in some countries is circumcision: for various cultural, religious, and more rarely medical reasons, part or all of the foreskin is removed
Edited sentence: The most prevalent form of genital alteration in some countries is circumcision: for various cultural, religious, and more rarely medical reasons, part or all of the foreskin is removed, though through careful hygenic care of the penis throughout life, circumcision is physiologically unnecessary