Abstract： Objective To investigate the value of using protective new intracolonic drainage in decreasing low colorectal anastomotic leakage.Methods One hundred and nineteen cases of rectal cancer accepted low anterior resection were randomly assigned to study group(n=55)and control group (n=64).The study group was added with a new intracolonic drainage composed of biofragmentable anastomosis ring and condom during operation.The control group was added with protective ileostomy during operation.The results of surgery were compared between the two groups.Results All the cases were followed up over three months and there were no perioperative death.There were no significant differences in physiopathologieal factors such as age, sex, body type, site of tumor, size of tumor,differentiation of tumor,site of anastomosis,condition of nutrition,concomitant disease between the two groups.In the study group,anastomotic leakage occurred in 4 cases(7.3%),the drainage devices were ablated 18.3 days after operations and there were no drainage-related complications;light anastomotic stenosis occurred in 3 cases(5.5%)three months after operations.Among the cases with leakage,no severe abdominal infection was found.the time of abdominal drainage was 4.8 days.and the amount of abdominal drainage was 1 2.8 ml/d in primary three days after leakage.In the control group,anastomotic leakage occurred in 7 cases(10.9%),stomy-related complications occurred in 29 cases(45.3%),anastomotic stenosis occurred in 18 cases(28.1%)and severe anastomotic stenosis occurred in 4 cases (6.3%)after three months.Among the cases with leakage, severe infection occurred in two cases,anastomotic spoiled occurred in one case,the amount of abdominal drainage was 35.4 ml/d in primary three days after leakage,and the time of abdominal drainage was 17.1 days.There was no significant difference in the rate of anastomotic leakage between the two groups(P＞0.05).But there were significant differences in the amount of abdominal drainage,the time of abdominal drainage and abdominal infection in the cases of anastomotic leakage(P＜0.01).There was significant difference in anastomotic stenosis after three months between the two groups(P＜0.01).Conclusions The intracolonic drainage is a simple,safe and effective method in protecting low colorectal anastomotic leakage,and avoiding harmful results caused by anastomotic leakage.Compared with protective ileostomy,intracolonic drainage can avoid stomy-related physical mental suffering and complications,the rate of later anastomotic stenosis is less,and the time of abdominal drainage is shorter in the cases with leakage.