Bit late back to the party as I had to go out, but:
spanisharmada, as other posters have pointed out, where do we draw the line? If everyone starts 'opting out' of providing the treatment they are paid by their employers to provide, then we eventually end up with a situation where someone from Kent has to go to Scotland to access the healthcare they are legally entitled to. No-one is suggesting banning people of certain religions from being a GP, but when you are acting in a professional capacity, (I say again) paid by your employer to provide a service, you have to check certain things at the door: pissy attitude, dislike of certain behaviours, and your own personal code of 'ethics'. If the patient is not asking you to break the law, and you are there to provide a service, it's not up to you to pick and choose which aspects of that service are ok with you.
You can follow any religion you choose, but you should not be allowed to inconvenience your patients by trotting out personal ethics, especially when they are based on sexist outdated beliefs. Should it be ok for doctors to not treat gay people, because their religion says so? Or women who don't cover their hair / bodies, because their cultural beliefs say so? I ask again, where do we draw the line?
You expect to get paid for doing your job, do your job. 100%, not just the parts you like.
I will add, I personally think circumcision is a bad thing, but I wouldn't for one second suggest a doctor didn't do it because of their 'ethics'. I wouldn't do it, which is why I'm not a doctor.