The effect of non-absorbable and rapidly absorbable suture material on the cytokinetics of crypt cells was studied in right and left colonic anastomoses in the rat by using stathmokinetic methods. Forty-five male Sprague-Dawley rats were allocated to three groups. In group A (n = 15), colonic anastomoses were performed in the right and left colon using nonabsorbable, stainless steel sutures. Groups B (n = 15) animals had identically located anastomoses but a rapidly absorbable suture material (Vicryl Rapide) was used. Animals of group C (n = 15) acted as controls. Eight weeks postoperatively, the crypt cell production rate (CCPR) was determined after measuring the slope of the metaphase accumulation line. At this time, no suture material was detected in any of group B (Vicryl Rapide) animals, while in group A rats (stainless steel), 79% of the animals had suture material in place. A steel-sutured anastomosis significantly increased the CCPR in the right colon from 6.2 to 10.6 cells/crypt/h and in the left colon from 5.6 to 9.8 cells/crypt/h compared with controls (p less than 0.05). An anastomosis performed with Vicryl Rapide, whether in the proximal or descending colon, did not influence the CCPR when compared with the control group (right 6.4 vs. 6.2 cells/crypt/h; left 4.2 vs. 5.6 cells/crypt/h). The CCPR at steel-sutured anastomoses was significantly higher than the CCPR at the Vicryl Rapide anastomotic site both in the right (10.6 vs. 6.4 cells/crypt/h) as well as in the left colonic sites (9.8 vs. 4.2 cells/crypt/h) (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)