An experimental model is proposed to study suture line recurrence. By giving enemas with K12 colon carcinoma cells, derived from a 1,2-dimethylhydrazine-induced colon cancer in male syngeneic BDIX rats, we were able to obtain a suture implantation in about 30% of the control animals. Possible systemic and local factors which might influence this implantation rate could be studied using this model. Only local irrigations of the colon lumen with sodium hypochlorite 0.2% prior to anastomosis produced a significant decrease in implantation rate. Irrigations with chlorhexidine-cetrimide 2.5%, the use of iodized suture material and altering the cellular immune system of the hosts by ciclosporin or excessive surgical stress, had no significant effect on the implantation rate.