Gastrectomy is a surgical operation that involves removing part of the stomach, specifically two-thirds, to form a tube. 

This surgical procedure is intended for patients who are dangerously obese, i.e. those who are overweight, affecting their physical health and quality of life on a daily basis. 

This operation reduces the patient’s appetite and therefore helps them to eat less every day. The results are visible after several months. It is the most common and drastic operation, which reduces the stomach to a volume of about 20ml, and also allows to lose any weight extract by reducing the feeling of hunger of patients. 

The food will therefore be slowed down as it passes through the tube and then evacuated very quickly into the small intestine.