Often we get asked how much stomach is removed during gastric sleeve surgery. This is quite variable from person to person and surgeon to surgeon. During surgery, a sizing tube is placed through the mouth and into the stomach. The patient is under general anesthetic. The stomach is cut around the tube meaning that all excess stomach bigger than the tube is removed. Therefore, some people have bigger stomachs to begin with and hence, more stomach will be taken. Generally about 60-70 percent of stomach is removed. The volume of stomach left behind is about 200-300mls, just enough to fit a small drink.