Gastroenterology (MeSH heading) is the branch of medicine whereby the digestive system and its disorders are studied. Etymologically, the name is a combination of three Ancient Greek words gastros (stomach), enteron (intestine), and logos (reason).
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 two to three years in the gastroenterology fellowship. 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.
Hepatology, or hepatobiliary medicine, encompasses the study of the liver, pancreas, and biliary tree and is traditionally considered a sub-specialty.

History

Citing from Egyptian papyri, Nunn identified significant knowledge of gastrointestinal diseases among practising physicians during the periods of the pharaohs. Irynakhty, of the tenth dynasty, c. 2125 B.C., was a court physician specialising in gastroenterology and proctology.

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.

Eighteenth century:

• Italian Lazzaro Spallanzani (1729–99) was among early physicians to disregard Galen's theories, and in 1780 he gave experimental proof on the action of gastric juice on foodstuffs.

• In 1767, German Johann von Zimmermann wrote an important work on dysentery.

• In 1777, Maximilian Stoll of Vienna described cancer of the gallbladder.

Nineteenth century:

• In 1805, Philip Bozzini made the first attempt to observe inside the living human body using a tube he named Lichtleiter (light guiding instrument) to examine the urinary tract, the rectum, and the pharynx. This is the earliest description of endoscopy.

• Charles Emile Troisier described enlargement of lymph nodes in abdominal cancer.

• In 1823, William Prout discovered that stomach juices contain hydrochloric acid.

• In 1868, Adolf Kussmaul, a well-known German physician, developed the gastroscope. He perfected the technique on a sword swallower.

• In 1871, at the society of physicians in Vienna, Carl Stoerk demonstrated an esophagoscope made of two telescopic metal tubes, initially devised by Waldenburg in 1870.

• In 1876, Karl Wilhelm von Kupffer described the properties of some liver cells now called Kupffer cell.

• In 1883, Hugo Kronecker and Samuel James Meltzer studied oesophageal manometry in humans.

Twentieth century:

• In 1915, Jesse McClendon tested acidity of human stomach in situ.

• In 1921-22, Walter Alvarez did the first electrogastrography research.

• Rudolph Schindler described many important diseases involving the human digestive system during World War I in his illustrated textbook and is portrayed by some as the "father of gastroscopy". He and Georg Wolf developed a semiflexible gastroscope in 1932.

• In 1932, Burrill Bernard Crohn described Crohn's disease.

• In 1957, Basil Hirschowitz introduced the first prototype of a fibreoptic gastroscope.

Twenty-first century:

• In 2005, Barry Marshall and Robin Warren of Australia were awarded the Nobel Prize in Physiology or Medicine for their discovery of Helicobacter pylori (1982/1983) and its role in peptic ulcer disease. James Leavitt assisted in their research, but the Nobel Prize is not awarded posthumously so he was not included in the award.

Disease classification

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

• Chapter XI,Diseases of the digestive system,(K00-K93)

2. MeSH subject Heading:

• Gastroenterology (G02.403.776.409.405)

• Gastroenterological diseases(C06.405)

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

• Digestive system(W1)

Gastroenterological societies

• World Gastroenterology Organisation

• American College of Gastroenterology

• American Gastroenterological Association

• American Society for Gastrointestinal Endoscopy

• British Society of Gastroenterology

Research Resources for Gastroenterology

• Scandinavian Journal of Gastroenterology (SGAS)

See also

• Gastroenterology (journal)