Diseases affecting the gastrointestinal tract, which includes the organs from mouth to anus, along the alimentary canal, are the focus of this specialty. Physicians practicing in this field of medicine are called gastroenterologists. They have usually completed the eight years of pre-medical and medical education, the yearlong internship (if this is not a part of the residency), three years of an internal medicine residency, and around two years in the gastroenterology residency. Specialists in GI radiology, hepatobiliary or gastric medicine, or in GI oncology will then complete a two- or three- year fellowship. Gastroenterology is not the same as gastroenterological surgery or of colon and rectal (proctology) surgery, which are specialty branches of general surgery. Important advances have been made in the last fifty years, contributing to rapid expansion of its scope.