Gastroenterology (MeSH headingcgi?mode=&term=gastroenterology" target="_blank">http://www.nlm.nih.gov/cgi/mesh/2007/MB_cgi?mode=&term=gastroenterology ) is the branch of medicine where the digestive system and its disorders are studied. Etymologically it is the combination of Ancient Greek words gastros (stomach), enteron (intestine) and logos (reason).

Diseases affecting gastrointestinal tract (i.e. _organs from mouth to anus) are the focus of this speciality. Doctors specialising in the field are called gastroenterologists. Important advances have been made in the last 50 years, contributing to rapid expansion of its scope.

Hepatology or hepatobiliary medicine encompasses the study of the liver, pancreas and biliary tree and is traditionally considered a subspeciality.