Gastroenterology

# Overview
Gastroenterology (MeSH heading ) 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 are 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.

# History
Citing from Egyptian papyri, Nunn identified significant knowledge of gastrointestinal diseases among practising doctors in Pharaoh periods. Irynakhty, of the tenth dynasty c. 2125 BC 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.
18th century:
- Italian Lazzaro Spallanzani (172999) 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 Zimmermann wrote an important work on dysentery.
- In 1777 Maximilian Stoll of Vienna described cancer of the gallbladder.
19th century:
- In 1805 Philip Bozzini made first attempt to observe living human body through 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 node in abdominal cancer.
- In 1868 Adolf Kussmaul, a well known German physician, developed the gastroscope. He perfected the technique on 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 1884 Kronecker and Meltzern studied oesophageal manometry in man.
20th century:
- Rudolph Schindler described many important diseases involving digestive system during World War I in his illustrated textbook and is portrayed by some as the "father of gastroscopy". He and Wolf developed a semiflexible gastroscope in 1932.
- In 1932 Burrill Bernard Crohn described Crohn's disease.
- In 1957 Basil Hirschowitz introduced the first prototype fibreoptic gastroscope.
- 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.

# 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
- American College of Gastroenterology
- American Gastroenterological Association
- American Society for Gastrointestinal Endoscopy
- British Society of Gastroenterology
- Canadian Association of Gastroenterology
- European Society of Gastrointestinal Endoscopy
- World Gastroenterology Organisation