A small part of the stomach is left on the side of the swallow tube from the upper part where the stomach joins with the entrance, and it is closed and cut so that almost 90% of the stomach is deactivated. In this way, a proximal gastric area smaller than 30 mL is created at the entrance of the stomach and this area is called gastric pouch. This newly created stomach pouch has a volume of almost less than 1 tea glass. In this surgery, the stomach is left in place and any part of it is not removed. By creating a stomach pouch, the existing stomach is eliminated, and thus food is provided to reach the pouch. It is taken from the part of the small intestines that goes towards the distal (large intestine) and cut about 100 cm and combined with the new gastric pouch to create a new feeding path. The proximal (initial) part of the cut intestine is connected to this newly formed feeding pathway. Here, the patient's food intake is severely reduced and he/she partially benefits from the food he/she takes due to malabsorption.