Dr. Goldstein reported on a large HMO in New York that served a population of over 286,000 people. This HMO hired a board certified colorectal surgeon in 1993. Charts of patients referred to this colorectal surgeon for anorectal complaints were reviewed for accuracy of diagnosis and appropriateness of care. A number of these patients had already been seen by a general surgeon.

The results of the study are an eye-opener. General surgeons made the correct anorectal diagnosis in only 53% of the time - in other words almost 1/2 the diagnoses were incorrect.

Inappropriate management by a general surgeon delayed the proper diagnosis in 25% of the patients and this led to a significant number having an adverse outcome.

Of those patients with anorectal symptoms treated by a general surgeon, most of the patients (79%) were not correctly treated!

These results are not suprising. You cannot expect general surgeons with limited training and limited experience to deliver the same caliber of care as a specialist colorectal surgeon. The average US general surgeon performs only an average of 3.4 hemorrhoid surgeries a year. (figures published in American Journal of Surgery January 1993 - see figure below).
Another study showed that Colon and Rectal Surgeons achieve a lower mortality with major abdominal surgery (1.4% vs 7.3% for general surgeons) and their rates for other complications are much lower because of their experience.

These low numbers of cases do not allow the average U.S. surgeon to attain proficiency or skill. The more surgery a surgeon does, the better are his/her clinical results. Since Colon and Rectal Surgeons perform only this kind of surgery, their success rate is much higher.
Even though it has been over 20 years since this paper was published, many more have shown that the results of care are improved if surgery is performed by experts with a large volume of clinical experience.