RESUMEN
To evaluate the evolution of ileorectal anastomoses, 20 male Wistar-TECPAR rats aged 120 days and weighing on average 274,5 g were divided at random into two groups of 10 animals each. The rats in group A were submitted to total colectomy and end-to-end anastomosis. The rats in group B were submitted to segmental resection of the left colon and end-to-end anastomosis. When the animals were sacrificed on the 14th postoperative day, group A animals were found to have lost more weight than group B animals (p = 0,01). Neither group showed dehiscence or peritonitis, but adhesions were present in both groups. Bursting pressure was lower in A rats (p < 0,05). Hydroxyproline content was lower in A rats but the difference was not significant and tissue protein was lower in group B (p < 0,05). Histologic evolution was similar in both groups. The conclusion was reached that the ileorectal anastomosis was not better than colorectal anastomosis in rats.