Causes of cardia achalasia: 1. loss of cardia muscle relaxation 2. loss of esophageal peristaltic capacity. The purpose of surgery is to cut the cardia muscle layer without damaging the mucosal layer, and the lower esophageal muscle is also cut, so that food enters the stomach mainly by gravity and the pressure in the lumen of the esophagus, and because there is no more muscle layer, a scar is formed between the mucosal layer and the surrounding tissues 3 weeks after surgery, and if diet training is not performed, scar stenosis may also form in the cardia, and we are making the patient must drink large mouthfuls of water every day 3 weeks after surgery, and each After the meal must walk for 30 minutes, which can prevent the scar formation of stenosis. It is also best to keep the head high and the feet in a 15-30 degree position during sleep. It is important to avoid eating too cold and too hot as well as stimulating foods after cardia relaxation surgery.