A retrospective review of patients who underwent double bowel resections and synchronous anastomoses without ileostomy or colostomy was undertaken. The study goal was to determine whether there was an increased incidence of complications attributable to the presence of a second anastomosis. A total of 66 patients who met the criteria were identified and divided into two groups. Group A consisted of 30 patients who had had two colonic resections and two colonic anastomoses. In Group B were 36 patients who had undergone separate colonic and small-bowel resections with two subsequent anastomoses. The indications for primary resection were: 1) adenocarcinoma, 54 percent; 2) Crohn's disease, 26 percent; 3) diverticulitis, 11 percent; 4) "other" indications, 9 percent. The indications for the second resection were: 1) metastatic adenocarcinoma, 30 percent; 2) Crohn's disease, 26 percent; 3) synchronous bowel lesions, 18 percent; 4) adhesions and enterotomies, 14 percent; 5) "other" indications, 12 percent. Overall, there were four major complications (6 percent), and 11 minor complications (17 percent). The sole anastomotic leak occurred in a patient who had undergone a double colonic resection (3%). The other major complications were one death, one ureteral complication that required reoperation, and one early small-bowel obstruction. Minor complications included two wound infections (3 percent), three seromas (5 percent), three prolonged ileus (5 percent), and three urinary infections (5 percent). These results are comparable to the best results reported for patients undergoing single colonic anastomoses. The conclusion is that it is safe to perform synchronous anastomoses without diversion provided the following conditions are present: well-prepared bowel with minimal fecal soilage, an adequate blood supply, technically good anastomoses, and lack of tension on the suture lines.