PURPOSE:The value of specialization has frequently been challenged by many health care institutions and providers. This review was conducted to determine whether there were any outcome differences in the management of fistulas complicating diverticulitis.METHODS:We conducted an historical cohort study using hospital charts of all cases of fistulas complicating diverticulitis that were operated on in four university‐affiliated hospitals between 1975 and 1995. There were 122 patients, with 37 under the care of fully trained colorectal surgeons and 85 under the care of general surgeons.RESULTS:There were no significant differences in patient demographics, preoperative comorbidities, or the number of preoperative diagnostic investigations between the two groups. The colorectal surgeons performed more intraoperative ureteral stenting (Colorectal Surgery 55.5 percentvs.General Surgery 24.4 percent,P=0.001). The general surgeons performed more initial diverting Hartmann's and colostomy procedures (Colorectal Surgery 5.4 percentvs.General Surgery 27 percent,P=0.013). The patients in the General Surgery group had longer preoperative lengths of stay (median Colorectal Surgery 3 (range, 1‐28) daysvs.General Surgery 8 (range, 0‐29) days;P<0.001), longer postoperative lengths of stay (median Colorectal Surgery 11 (range, 5‐40) daysvs.General Surgery 14 (range, 2‐80) days;P=0.001), and longer total lengths of stay (median Colorectal Surgery 14 (range, 6‐62) daysvs.General Surgery 24 (range, 6‐100) days;P<0.001). The patients in the General Surgery group experienced a higher rate of wound infections (Colorectal Surgery 5.4 percentvs.General Surgery 12.9 percent), and a larger proportion of them experienced complications (Colorectal Surgery 27 percentvs.General Surgery 41.2 percent).CONCLUSIONS:We conclude that specialization in colon and rectal surgery contributed to an improved outcome, with a lower rate of diverting procedures, a shorter hospital stay, and a lower rate of complications.