Stomach colon rectum diagram-en.svg
Illustration of the stomach, colon and rectum.
Significant diseasesGastrointestinal cancers, Gastrointestinal bleeding, Liver cirrhosis, Gallstones, Gastroenteritis, Inflammatory bowel disease
Significant testsColonoscopy, Stool test, Barium swallows, Endoscopy
GlossaryGlossary of medicine
  • Physician
  • Surgeon
Occupation type
Activity sectors
Medicine, Surgery
Education required
Fields of
Hospitals, Clinics

Gastroenterology[1] is the branch of medicine focused on the digestive system and its disorders.

Diseases affecting the gastrointestinal tract, which include the organs from mouth into anus, along the alimentary canal, are the focus of this speciality. Physicians practicing in this field are called gastroenterologists. They have usually completed about eight years of pre-medical and medical education, a year-long internship (if this is not a part of the residency), three years of an internal medicine residency, and three years in the gastroenterology fellowship. Gastroenterologists perform a number of diagnostic and therapeutic procedures including colonoscopy, esophagogastroduodenoscopy (EGD), endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound (EUS), and liver biopsy.[2] Some gastroenterology trainees will complete a "fourth-year" (although this is often their seventh year of graduate medical education) in transplant hepatology, advanced interventional endoscopy, inflammatory bowel disease, motility, or other topics.

Advanced endoscopy, sometimes called interventional or surgical endoscopy, is a sub-specialty of gastroenterology that focuses on advanced endoscopic techniques for the treatment of pancreatic, hepatobiliary, and gastrointestinal disease. Interventional gastroenterologists typically undergo an additional year of rigorous training in advanced endoscopic techniques including endoscopic retrograde cholangiopancreatography, endoscopic ultrasound-guided diagnostic and interventional procedures, and advanced resection techniques including endoscopic mucosal resection and endoscopic submucosal dissection. Additionally, the performance of endoscopic bariatric procedures is also performed by some advanced endoscopists.

Hepatology, or hepatobiliary medicine, encompasses the study of the liver, pancreas, and biliary tree, and is traditionally considered a sub-specialty of gastroenterology, while proctology encompasses disorders of the anus, rectum, and colon and is considered a sub-specialty of general surgery.


Drawings of Bozzini's "Lichtleiter", an early endoscope
Drawings of Bozzini's "Lichtleiter", an early endoscope

Citing from Egyptian papyri, John F. Nunn identified significant knowledge of gastrointestinal diseases among practicing physicians during the periods of the pharaohs. Irynakhty, of the tenth dynasty, c. 2125 B.C., was a court physician specializing in gastroenterology, sleeping, and proctology.[3]

Among ancient Greeks, Hippocrates attributed digestion to concoction. Galen's concept of the stomach having four faculties was widely accepted up to modernity in the seventeenth century.[citation needed]



McClendon's pH-probe
McClendon's pH-probe


Twenty-first century:

Disease classification

1. International Classification of Disease (ICD 2007)/WHO classification:

2. MeSH subject Heading:

3. National Library of Medicine Catalogue (NLM classification 2006):

Gastroenterology community

Gastroenterological societies




In the United States, gastroenterology is an internal medicine subspecialty certified by the American Board of Internal Medicine (ABIM) and the American Osteopathic Board of Internal Medicine (AOBIM).[citation needed]

Research resources


  1. ^ MeSH heading gastroenterology
  2. ^ "Gastroenterology". American Medical Association. Retrieved 11 July 2020.
  3. ^ Nunn JF. Ancient Egyptian Medicine. 2002. ISBN 0-8061-3504-2.
  4. ^ Edgardo Rivera, MD James L. Abbruzzese, MD; Pancreatic, Hepatic, and Biliary Carcinomas, Medical Oncology: A Comprehensive Review [1]
  5. ^ DeStoll M: Rationis Mendendi, in Nosocomio Practico vendobonensi. Part 1 LugduniBatavarum, Haak et Socios et A et J Honkoop 1788, OCLC 23625746
  6. ^ Gilger, MA (October 2001). "Gastroenterologic endoscopy in children: past, present, and future". Current Opinion in Pediatrics. 13 (5): 429–34. doi:10.1097/00008480-200110000-00008. PMID 11801888. S2CID 39462852.
  7. ^ The Origin of Endoscopes, Olympus history
  8. ^ Anton Sebastian, A Dictionary of the History of Medicine, ISBN 1-85070-021-4
  9. ^ Prout, W. On the nature of the acid and saline matters usually existing in the stomachs of animals. – Philos. Transactions, 1824, 1, 45.
  10. ^ McClendon J. F. New hydrogen electrodes and rapid methods of determining hydrogen ion concentrations. – Amer. J. Physoil., 1915, 38, 2, 180.
  11. ^ Alvarez WC (1922). "The electrogastrogram and what it shows". JAMA: The Journal of the American Medical Association. JAMA. 78 (15): 1116. doi:10.1001/jama.1922.02640680020008. Retrieved 22 May 2020.