Would have replied earlier but this crazy server is driving me crazy! (5 minutes to load a reply page?!) Can't wait for the new server to really kick in.
Anyway, to the question at hand. Colorectal surgery is one of the few general surgery subspecialties to have its own independent board (Thoracic and Plastics being the only other two, while vascular is making a bid now). The main society is the American Society of Colon and Rectal Surgery (ASCRS) which can be found at
www.fascrs.org Click on the residency training button to see what programs are available.
Currently only 1 year of residency (note that this is technically a residency just as CT surg is technically a residency since it leads to a separate independent board certification) is required, although some programs include a 2nd year for research, the mode is definitely one.
Colorectal surgeons obviously focus on those two things. They probably stand out the most when you talk about complex pelvic and anal work (e.g. high transanal excision, continence restoration, etc.) as well as all the standard things that a cutting edge general surgeon might do (ileal pouches (J-pouch) for UC, colon cancer resections, etc.) Also, all colorectal surgeons do a fair bit of endoscopy training and incorporate it into their practice much more so than general surgeons, especially as it related to therapeutic endoscopy.
Historically, Colorectal surgery was not a specialty that was well represented in academia, however that is definitely changing, and in looking around, most academic centers now either have a board-certified colorectal surgeon or are in the process of recruiting one. Still, you will find that colorectal surgery is less well defined than the other specialties at many centers. As far as competitiveness, the days of it being uncompetitive are largely over. There are ~30 programs offering about ~50-60 spots and the number applying easily exceeds that in most years these days. The admission process is a match run by the NRMP, applications at the beginning of your chief year.
I hope this helps.