You probably mean DO instead of OD. A DO is a doctor of osteopathy. MD is considered allopathy (not osteopathy). I'm not a DO, but the basic philosophy is of a more holistic approach, including "manipulation" as one of the additional classes in the curriculum. From what I understand, it is different from chiropractic manipulation, but it involves moving the body in certain ways that is supposed to heal various ailments.

The actual DO curriculum is virtually identical to medical school, except that there is the additional course in manipulation. DO's do have their own residency programs, but many will choose to go to an MD residency program.

In general, DO programs are less competitive than MD programs to get into. Also, DO's are usually at a disadvantage when applying to residency programs, especially competitive programs. It seems that most doctors who go through DO programs specialize in more of the primary care fields. In the end, though, I think even the most competitive residency programs will consider applications from DO programs, assuming they have done well enough.

I'm curious to see the evidence-base for manipulation - we didn't get exposed to it in allopathic medical scool.

OD = Doctor of Optometry.
That's the guy/gal who does refraction and writes the script for your new glasses or contacts. Optometrists can't prescribe meds or anything like that, although they are pushing for it in some states.

MD = Medical Doctor (allopathic physician)
This is the physician most people think of when they hear the title "Doctor." MDs are called "complete physicians" in that they can use any treatment modality, drugs/surgery/etc.

DO = Doctor of Osteopathy (osteopathic physician)
This is the kind of physician described by Doc Admin above. Osteopathic physicians are also "complete physicians" who utilize drugs/surgery/etc. In addition, DOs are trained in osteopathic manipulative medicine, which uses the hands as tools in diagnosis and treatment of certain ailments. In every other regard, DO medical school is just like MD medical school, however (right now, for example, embryology is probably just as much of a pain in the butt for me as for most MD students!).

DOs practice in all specialties, and can complete either MD or DO residencies. The additional training in manipulation is one of the things that drew me to a DO school in the first place, actually.

The prejudice Doc Admin mentioned in his posting, while very real in some instances (especially friction between older MDs and older DOs, who went through a lot of political friction), is more a thing of the past in my experience -- DOs are integrated into all specialties in medicine, and have served as the Surgeon General of the Army Medical Corps, and can be found completing residencies at Harvard and Yale. Close to 20% of the military physicians in the US are DOs.

There are about 20 DO schools in the US, compared to ~116 MD schools, so DOs are in the minority, numbers-wise. Admission to a DO school is competitive, certainly, and some of my classmates selected our DO school over some fine MD programs. It all comes down to personal preference, in most cases. DO schools do seem to have a tendency to focus on the "whole applicant" rather than honing in on solely on GPAs and MCATs, but you need to be competitive.

(Oh, and I will post a couple of references about OMM later, Doc Admin... I meant to do it before and totally spaced it!)

Feel free to hit me with any questions about DO school, DOs in general, or anything thereunto appertaining. Good luck! 😎