Ritual Circuмcision is forbidden strictly. See Laeteran IV, I think.
Medical circuмcision is not the same thing at all, nor is it done for the same reasons. It's like the difference between piercing your ear and lopping it off.
That being said, it's a fraudulent and mutilative practice which generations of people, including Catholics, have been conned into thinking has medical benefits. It shouldn't be done and the word should be spread, but for these reasons, not because it's the same as ritual Circuмcision (which it substantively isn't).