Four years after rectal cancer surgery, now it hurts around the anus as soon as defecation, which is usually related to rectal swelling, inflammation and infection, anastomotic fistula, and can be treated conservatively or surgically according to the condition. 1. Rectal swelling: some rectal cancer patients may repeatedly stimulate rectal area due to constipation after surgery, thus causing rectal swelling and anal pain. When dealing with it, oral ibuprofen can be taken to relieve pain, and at the same time, it is necessary to keep the bowel movement smooth to prevent constipation, and also daily anal warm water sitz bath after defecation and before going to bed can be taken to promote local blood circulation and relieve rectal edema and pain. 2. Inflammatory infections: If you do not pay attention to personal hygiene after surgery, infected by defecation and perianal pollutants, inflammatory stimulation will cause pain in the anal opening. Cephalosporin should be taken orally as prescribed by the doctor, and at the same time, erythromycin ointment or mupirocin ointment should be applied to the anal opening to reduce the inflammatory stimulus reaction. 3. Anastomotic fistula: it is mainly related to poor healing of anastomosis, and local drainage can be carried out for treatment, and if the suture is not in place, the anastomotic nail needs to be taken out through surgery. After rectal cancer surgery, if anal pain occurs after defecation, it is recommended to consult the doctor in time and conduct relevant examination under the guidance of professional doctors to understand the cause and then deal with it in a targeted way. During the period, we should also pay attention to diet, try to be light and easy to digest as the principle, which can reduce the stimulation to the rectum.