Dozens of surgical procedures have been developed, which can be divided into 3 main categories according to the mechanism: intake restriction, absorption reduction and combined procedures. The mechanism of action of the intake restriction type is to reduce the volume of the gastric lumen and reduce the amount of food; the mechanism of action of the absorption reduction type is to reduce the absorption area of the duodenum and upper jejunum; the combined type is to combine the reduction of the gastric lumen and diversion. However, while surgical procedures are being carried out with great success, our endoscopists are not shy to develop a number of effective and safe bariatric endoscopic procedures based on a series of special endoscopic systems. Here is a brief introduction to some of these procedures. 1. Gastroscopic BioEnterics Intragastric Balloon (BIB). BioEnterics Intragastric Balloon (BIB) is a silicone polymer balloon with a volume of about 600-800 ml. When the balloon is placed in the stomach, saline mixed with methylene blue is injected into it, so that the expanded balloon occupies the stomach lumen and reduces the effective volume of the stomach. The maximum duration of balloon placement is 6 months, because the balloon is prone to spontaneous deflation at this time. Since the balloon is filled with methylene blue solution, if leakage or rupture occurs during use, etc., the leaked methylene blue solution will be absorbed into the blood by the mucosa, thus causing the urine to turn blue, whereby it can be used as an indication to judge the status of the balloon in the stomach. The meta-analysis suggested that the main adverse effects after BIB placement included malignancy, vomiting, intestinal obstruction (0.8%), and gastric perforation (0.1%), while the mean decrease in BMI was 5.7. Also, in a study on the long-term weight loss effects of BIB, 500 obese patients were enrolled in the study for a 5-year follow-up. It was found that in the final 41% of effective patients, the weight loss success group, i.e. >20% excess weight loss (EWL), had a mean BMI reduction of 2.5, suggesting that BIB therapy is a durable and reliable method of weight loss. 2. Transoral Gastroplasty (TOGA) The endoscopic system used for TOGA consists of two main parts: the fixator and the anastomosis. The fixator contains a looped constriction wire and a central septum that holds the stomach wall tissue in place. The anastomosis consists mainly of a vacuum pump and a titanium clamp anastomosis device. The sleeve anastomosis is performed after the vacuum pump attracts the fixed gastric wall tissue to the sleeve, thereby reducing the volume of the gastric lumen. Several clinical trials have confirmed that TOGA can effectively reduce the BMI of obese patients, and there are no serious postoperative complications. 3.POSE (Primary Obesity Surgery Endolum enal) Incisionless Operating Platform (Incisionless Operating Platform, IOP) is an endoscopic device that can enter the gastric cavity through a stable channel of natural orifices (such as the digestive tract) developed by USGI Medical, and perform incisionless surgery. The POSE procedure is primarily based on the IOP system, which creates artificial folds in the gastric body and distal stomach using a special suture anchor to reduce the volume of the gastric lumen. The results of the 6-month follow-up after POSE in 45 subjects (mean BMI of 36.7) suggested a mean weight and BMI loss of 16.3 Kg and 5.8. There were no postoperative deaths and the main adverse effects were gastroparesis, sore throat, malignancy, and vomiting. 4. Endoscopic sleeve gastroplasty (ESG) This procedure is based on the Endoscopic Suturing System developed by Apollo Endosurgery (OverStitch?), which performs a series of interrupted sutures from the gastric sinus to the gastroesophageal junction. A series of intermittent sutures are used to reduce gastric volume. The procedure was successfully performed on four obese patients with a BMI greater than 33. All patients developed intraoperative complications, and three patients developed postoperative complications such as abdominal pain and malignancy, which were relieved with symptomatic treatment. Clinical trials on the evaluation of its efficacy are underway. 5. Endoluminal vertical gastroplasty (EVG) This procedure reduces the volume of the gastric cavity by sequentially inserting stitches in the anterior and posterior walls of the stomach and finally tightening the sutures to make the anterior and posterior walls of the stomach close together. The procedure was performed on 68 patients with a mean BMI of 39.9, and after 12 months of follow-up, the mean BMI was found to have decreased significantly to 30.6. No significant side effects were observed in any of the patients. 6. articulating circular endoscopic stapler (ACE stapler). The device is a 16-mm wide outside diameter endoscopic system in which a 5-mm diameter endoscope is placed. The front of the anastomosis has a negative pressure suction device that draws the gastric wall tissue into a slot and then stares at the root of the protruding gastric wall with eight rows of titanium clips, thus creating an artificial circular fold. Seventeen obese patients with a mean BMI of 40.2 were included in the study for the ACE procedure. The average weight loss after one year of follow-up was 34.9%. The main postoperative adverse effects were gastroparesis, sore throat, and malignancy. Second, absorption-reducing EndoBarrier therapy consists of endoscopic placement of a duodenojejunal bypass liner (DJBL). The dilated sleeve can occupy the entire intestinal lumen. When feeding, the chyme enters the interior of the sleeve and is infused into the distal jejunum. The bile and pancreatic juice secreted at this time are isolated from the chyme and are infused along the outer wall of the sleeve to the distal jejunum and then mixed with the chyme, thus reducing the absorption of chyme in the small intestine. Several clinical studies have been conducted to demonstrate the effectiveness and safety of this method. In conclusion, endoscopic weight reduction surgery is currently an effective and feasible method in the short term, and the adverse effects of various procedures are mainly gastroparesis, sore throat, and malignant vomiting due to endoscopic operation. The promotion of these procedures still requires further multicenter, large sample size prospective studies. At the same time, the sustainable effect of weight reduction surgery and the potential long-term effects on individuals after the change of normal physiological state of the stomach and intestines should also be the focus of future research.