As the incidence of anorectal diseases increases, more and more people are undergoing anorectal surgery. The slowing down of heart rate, decrease of blood pressure, arrhythmia, myocardial ischemia, and even cardiac arrest can be caused by pulling or dilating the anorectum during anorectal surgery, and sometimes serious consequences can occur. In particular, during PPH surgery, vagal reflexes often occur due to pulling during the tightening of the purse string, tightening of the anastomosis and firing, which may cause lower abdominal pain, nausea, vomiting and irritability in mild cases, and heart rate and blood pressure to drop or even shock in severe cases, which should be taken seriously by clinicians. Today, we will learn about the “anal reflex” together. Mechanism of anal reflex: The vagus nerve is richly distributed in the rectal area, and the vagus nerve stress increases during surgery. Repeated stimulation during surgery can cause coronary artery spasm and myocardial ischemia through rectal-heart reflex or vagus-vagus reflex, resulting in a decrease in heart rate and blood pressure, or even cardiac arrest. When the visceral sympathetic nerve is blocked by epidural anesthesia, the blocking plane reaches the thoracic 4 to lumbar 1, but the vagus branch cannot be blocked, so it is easy for the vagal reflex to occur during surgical operation. How to prevent the anal heart reflex: 1. Adequate preoperative preparation (1) The probability of the anal heart reflex is high in elderly patients with combined cardiac disorders, correcting the original disease, giving preoperative medication to nourish the myocardium and improve myocardial metabolism, avoiding unnecessary emergency surgery, and requesting a consultation with a cardiovascular surgeon if necessary. (2) Preoperative correction of water-electrolyte balance disorder. More attention should be paid to those who are afraid to eat normally due to painful bleeding stools and who undergo multiple cleansing enemas before surgery. (3) Preoperative intraosseous injection of atropine and diazepam is helpful to increase the heart rate and reduce the pulling reflex. (4) Rational choice of anesthesia. Most minor anorectal surgeries can be completed under sacral or local anesthesia, and continuous epidural anesthesia can be chosen for emergencies, abnormal ECG, more serious conditions, and long operation time, which can improve the quality of surgery and reduce or eliminate anal heart reflexes and increase the safety of surgery. (1) Closely observe the changes of heart rate, blood pressure and ECG, and prepare resuscitation items in order to detect and deal with serious anal heart reflexes in time. (2) The operator should move gently and quickly to avoid excessive stretching. If anal heart reflex occurs, the operation should be stopped immediately, and intravenous atropine and ephedrine should be injected, and the heart rate should rise to 70 times/min, and the blood pressure should rise to the basal blood pressure and above, and then operate for 2 min. (3) If cardiac arrest occurs, immediate chest compressions, mask artificial respiration, timely tracheal intubation, supplemented with epinephrine, atropine, ephedrine, after resuscitation, intermittent use of atropine, close cardiac monitoring to complete the operation, if necessary, stop the operation. (4) Those who are highly nervous should give the necessary explanation during operation, obtain cooperation, and strengthen psychological counseling work.