Gastroenterology is the branch of medicine whereby the digestive system and its disorders are studied. 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. 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.