My girlfriend and I do it fairly regularly, we’re exclusive and neither of us has anything nasty so we never bother with condoms. I’ve never had any sort of infection (touch wood). 95% of the time my dick comes out completely clean, or at least completely clean-looking; there’s only ever been a tiny bit of mess on a couple of occasions. I don’t think enemas are necessary really, just make sure you time it so your partner’s taken a shit in the last couple of hours.
That said, it probably depends on how much fibre she eats and general digestive health. If you find there is usually a bit of mess it might be a good idea to use condoms, even if just to avoid the ‘yuk’ factor of getting a dirty dick. But otherwise I think they’re superfluous.