There isn't, to my knowledge, any naturally-occurring equivalent of a circumcised penis. Its about as natural and necessary as nose-jobs or breast implants. Its a religious-driven practice, nothing more. Doctors used to remove tonsils and adenoids as a matter of course but now we know it can actually compromise an adult's immune system to do so. Even the obvious rebuttal of our 'vestigial' appendix seems to have a function in our immune system.... Evolution has had a very long time to work out these kinds of things and its silly to think we know better.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh