Postoperative anastomotic narrowing of rectal cancer can be treated by secondary surgery, and the secondary surgery can treat the stenosis by dilatation treatment, hanging wire treatment and stent placement treatment. Postoperative anastomotic narrowing after rectal cancer can be treated by surgery, which can be performed by loop cutting the stenosis under enteroscopy and then dilatation, and dilatation treatment can be performed by using dilator or balloon; stenosis can also be treated by enteroscopic multi-point stenotomy and hooking up the threads; however, there is still a possibility of re-stenosis after secondary surgery, so stent placement treatment can also be performed. Narrow anastomosis after rectal cancer surgery may be caused by long time not discharging stool from anus and local scar formation of anastomosis. Patients can first use fingers to assist and dilate the anal canal to help defecation, if they can defecate, then they can not undergo surgery, if they still cannot defecate, then they need to undergo surgery. If anastomotic stenosis occurs after rectal cancer surgery, please follow the doctor’s instruction for treatment.