GASTROENTEROLOGY

medical specialty concerned with the digestive system and its diseases. The first scientific studies of the digestive system were performed by Jan Baptist van Helmont in the 17th century. In 1833 the publication of William Beaumont's observations threw new light on the nature of gastric juice and the digestive process in general. A major advance in treatment in the 19th century was the use of gastric lavage (washing out of the stomach) to treat stomach poisoning; this became a standard treatment for all forms of gastric irritation, and the long tube used to introduce the lavage fluid was also adapted to view the stomach for diagnostic use. The first truly useful instrument for viewing the stomach, a tube that could be inserted down the esophagus and upon which a light was mounted to illuminate the area visualized, was invented in about 1889; this rigid instrument was soon replaced by the flexible gastroscope, developed by Rudolph Schindler in 1932. In the 1890s Walter Cannon used X rays to visualize the stomach and digestive organs, and he also used bismuth salts to coat the gastrointestinal lining and thus make digestive movements visible by fluoroscopy. Major diagnostic advances in the 20th century included the development by Bertram W. Sippy of a dietary schedule for healing peptic ulcers, and surgical vagotomy, in which the vagus nerve is severed to eliminate stomach-acid secretion, an operation first performed by Lester Dragstedt in 1943. Modern-day gastroenterologists diagnose and treat the diseases and disorders of the stomach, intestines, liver, and pancreas. Among the most common disorders they must deal with are gastric and duodenal ulcers, malignant tumours, inflammatory bowel diseases, and rectal disorders. In the past decades, highly effective drug treatments that have been developed minimize the need for surgery for patients with ulcers.