Objective To explore the effect of endoscopic submucosal dissection in the treatment of early colorectal cancer and precancerous lesions. Methods One hundred and thirty-eight patients with early colorectal cancer and precancerous lesions admitted to a hospital in Henan Province from March 2018 to March 2020 were selected for the study. The patients were divided into a study group（n=69） and a control group（n=69） using the random number table method. Patients in the control group were treated with endoscopic mucosal resection

while patients in the study group were treated with endoscopic mucosal dissection. The operation time（time from entering to leaving the operating room）

intraoperative blood loss（blood loss calculated by weighing method and volume method）

bed rest time（time from leaving the operating room to the first independent ambulation） and hospitalization time（time from checking in to checking out） were compared between the 2 groups. The levels of motilin（MTL）

somatostatin（SS） and D-lactic acid（D-LA） of the 2 groups of patients were compared before surgery and at 3 days after surgery. Complications during the 3-month postoperative follow-up period were compared between the 2 groups. Results The bed rest and hospitalization was shorter in the study group than in the control group

with statistically significant differences（P<0.05）

and the amount of intraoperative blood loss was less in the study group than in the control group

with statistically significant differences（P<0.05）. There was no statistically significant difference in MTL

SS

and D-LA levels between the 2 groups of patients before surgery（P>0.05）. At 3 days after surgery

the MTL and SS levels were lower than those before surgery in both groups

but higher about the MTL level in the study group than in the control group. The differences were statistically significant（P<0.05）. The D-LA levels were higher than those before surgery in both groups

but lower in the study group than in the control group

and the differences were statistically significant（P<0.05）. The complication rate of patients in the study group was 2.9%

which was lower than that in the control group

which was 14.5%

and the difference was statistically significant（P<0.05）. Conclusion The effects of endoscopic submucosal dissection in the treatment of early colorectal cancer and precancerous lesions are obvious. It can shorten the physical recovery time of patients after surgery

reduce the functional damage of patients’ gastrointestinal tract caused by surgery

and decrease the incidence of postoperative complications

and has clinical promotion value.