A surgeon who specializes in treating diseases the parts of the body which involved in digestion. These include the esophagus, stomach, small intestine, large intestine, rectum, liver, gallbladder and pancreas. The surgery may be used to remove growing cancer or non-cancer or damaged body parts, such as the intestines. It can also be used to repair problems such as hernias. This surgical procedure is used for screening and diagnose problems with the digestive system.