Laparoscopic gastric bypass surgery is one of the strategies oriented towards weight reduction in obese patients. Although in the short term it has a high degree of success, weight regain is common in the long term, in part due to the dilatation of the anastomosis that allows food to pass without barriers and hinders the purpose of bypass surgery. Fulguration with argon is an endoscopic technique that reduces the diameter of the anastomosis, offering resistance to food passage and improving patient outcomes.