Digestive system surgery or gastro intestinal surgery, can be divided into upper GI surgery and lower GI surgery. Upper gastro intestinal surgery (upper GI surgery, like esophagus, stomach, duodenum and ileum) refers to a practice of surgery that focuses on the upper parts of the gastro intestinal tract. There are many operations relevant to the upper gastro intestinal tract that are best done only by those who keep constant practise, owing to their complexity.