Can you work in an ER if you are an IM doctor? I know that FP docs work in smaller ERs but can IM docs do this also.
You can try, but it is unlikely that an ED will hire a straight IM-trained doctor. When was the last time you intubated someone? How much trauma experience do you have? I mean, it can be done, but is falling away. The FM folks find their way in still because EM is very broad, as is FM training - however, there are a few things that FM still doesn't do (like trauma). It's a closer fit, but still not EM.
Now, would you want an EM doc treating the IM clinic patients? I sure wouldn't (having done an IM year - even if it was prelim). FM docs could treat those patients, but, still, it's not the perfect fit. You want the right person for the right job.
The Harborview example is unique, in that there are no other civilian EM residency programs that have non-EM boarded faculty running them (ABEM - the American Board of Emergency Medicine - states that you can have non-EM trained people on faculty, but the core has to be EM-trained and BC/BE - or, as the parlance now goes, "BC/BP") - that is why the UW civilian program is no longer, and it's military only now.
The Harborview ED runs like the stereotype people have of the ED - doing not much, and consulting out the butt. The more the doc in the ED does, the less he calls someone else, and the smoother things go.