Since its founding in 1978 by Robert GIULI, M.D., FACS, Professor of Surgery at the University of Paris, the structure of OESO has been that of an informal international network, created to set up polydisciplinary multicenter studies on esophageal disease.

From the start, the unique goal of this endeavor has been to bring together specialists from all disciplines involved in the then new science of esophagology, in order to carry out research in the diverse fields contributing to better care of patients suffering from a disease of the esophagus.

The first President of Honor of OESO was Professor J.L. LORTAT-JACOB (Paris). Then, and up until 2000, Professor Guido N.J. TYTGAT (Amsterdam), world renowned gastroenterologist, and Professor Tom R. DeMEESTER (Los Angeles), equally renowned in the field of esophageal surgery, shared this role.

In 2004, OESO counts 11,000 corresponding members in 85 countries of the world.

Professor Robert Giuli has acted as the Scientific Director of the network since its creation.

Moreover, a Permanent Scientific Committee was constituted: originating from some 20 countries and representing 18 different disciplines, its 80 members gave form to the international and polydisciplinary nature of OESO.
The mission of this Permanent Scientific Committee is to draw up the list of the polydisciplinary work likely to be organized for multicenter research in all the areas of esophageal disease, and to make up the program of the triennial OESO World Congresses.

By its original, polydisciplinary nature, by its multicenter research program, by its international assembly of the world's leading specialists from 18 different disciplines, all interested in a single organ, the esophagus,

OESO has represented a unique joint endeavor, and has progressively attained since its foundation the status of a world reference in the domain of esophagology.

The OESO carries out several types of scientific activities:
- Polydisciplinary multicenter studies,
- Studies carried out on the protocols selected by the Permanent Scientific Committee,
- Scientific work sessions, held on a six-monthly or annual basis.

These meetings took place in Lausanne (Switzerland), then in Paris, and in various cities of the United States.
Bringing together the members of the Scientific Committee, they comprised reports on projects underway and discussions of proposals for future work. They also provided an opportunity to establish the objectives for the OESO Congresses to come:

The OESO World Congresses occur every 3 years, each dealing with a very focused topic of esophagology on which an international update was provided, following a unique format:

Since the first one, the program of these meetings has always been composed of several hundred pithy questions whose sequence attempted to cover in all the disciplines, by a sort of dissection of the selected topic, the persisting areas of controversy or doubt.
To answer each question, "the" expert from any part of the world is then contacted, who, through a concise summary of his or her personal experience, seems best able to provide a comprehensive answer in but a few minutes.
At the same time, topic forums, parallel symposia and workshops, involving world renown experts in their respective fields, brought the scientific exchanges taking place in the OESO Congresses to a particularly high level.
Up until the year 2003, 7 OESO Congresses, lasting 3 to 6 days and bringing together 600 to 1,500 attendees, dealt with:

1984 (May 17-19): Cancers of the Esophagus, 135 Questions.
1987 (June 24-27): Benign Lesions of the Esophagus and Cancer, 210 Questions.
1990 (June 19-23): Primary Motility Disorders of the Esophagus, 450 Questions
1993 (September 1-4): The Esophageal Mucosa, 300 Questions.
1996 (September 3-7): The Esophagogastric Junction, 420 Questions.
2000 (September 1-6): Barrett's Esophagus, 250 Questions.
2003 (Aug. 31- Sept. 4): The Duodeno - Gastro - Esophageal Reflux, 155 Questions.

The last four Congresses took place in the emblematic setting of UNESCO in Paris. The 5th and 6th were also granted the personal patronage of the President of France, Mr Jacques CHIRAC.

Following each Congress an encyclopedic book was regularly published, assembling the detailed responses to the questions posed on this occasion, with a whole additional series of questions and answers specifically designed for the publication.
These books were therefore in no way the proceedings of a congress: each, in fact, was a sequence of structured scientific articles, with illustrations, tables and complete bibliographical references focused on one single question, thus offering the reader an exceptional synthesis of facts, ideas and concepts presented by the world's greatest experts.
Each volume was made up of approximately 900 to 1600 pages, and a kind of an evolutionary encyclopedia was thus progressively composed, which every three years covered a comprehensive chapter in an area of esophagology.

Whatever their respective field of interest, readers thus have at their disposal an exceptional source of references: opening the book at random, to any page, they find at once the detail they are looking for, the professional opinion they need, or the development of a question they have perhaps not yet asked themselves.
The titles of the preceding OESO books are:

1985: Cancers of the esophagus. Answers to 135 questions.
(Maloine) 430 p. R. Giuli Ed.
1988: Benign lesions of the esophagus and cancer. Answers to 210 questions.
(Springer Verlag) 850 p. R. Giuli, R.W. McCallum Eds.
1991: Primary motor disorders of the esophagus. 450 questions - 450 answers.
(J. Libbey Eurotext) 1220 p. R. Giuli, R.W. McCallum, D.B. Skinner Eds.
1994: The esophageal mucosa. 300 questions - 300 answers.
(Elsevier) 1200 p. R. Giuli, G.N.J. Tytgat, T.R. DeMeester, J.P. Galmiche Eds.
1998: The esophago-gastric junction. 420 questions - 420 answers.
(J. Libbey Eurotext) 1620 p. R. Giuli, J.P. Galmiche, G.G. Jamieson,
C. Scarpignato Eds.
2003: Barrett's esophagus. 250 questions - 250 answers.
(J. Libbey Eurotext) 850 p. R. Giuli, J.R. Siewert, D. Couturier,
C. Scarpignato Eds.

The very specific scientific value acquired by the OESO global network in the field of esophagology justified turning it into an instrument for the active acquisition, permanent updating and dissemination of knowledge within each of the different branches of gastroenterology.
The possibility for access to expertise using current, low cost, technical resources make Telemedicine a necessary component of the health-care system today, satisfying the requirement for a multi-partner cooperation.

The OESO Foundation (Health Operating Polydisciplinary Expertise Services) is an original enterprise, built on the collaborative previous working experience of over 20 years acquired through OESO, in which polydisciplinary skills, at the highest international level, were combined to focus on a single organ, the esophagus.
In a similar, but more ambitious perspective, the OESO Foundation is setting up a worldwide, web-based services of information, updating, and Continuing Medical Education, extended to all digestive organs and dealing with all medical disciplines, for a global approach to the health-care requirements of populations.

The polydisciplinary potential magnitude of this network has been enhanced by the official recognition granted to OESO by UNESCO: a RESOLUTION, officially approved at the time of the 30th General Conference of the 187 member States (October-November 1999), considers the advantages of extending the network of excellence represented by OESO to other organs to transform it into an active tool of gaining, of updating, and of spreading knowledge in each of the branches of gastroenterology.
The interest UNESCO has shown in the projects of OESO has been explicitly motivated by its innovative character and, in particular, by the opportunity made available to populations of developing countries to become effectively involved in the network at a moderate cost, and to have access to a virtual library or to international discussion forums.

Since the founding of OESO in 1978 as an informal entity, the originality of its multidisciplinary approach has given to this network a particular place in the international Community, and its novel, highly specific character as a clinical and basic research body.
OESO and The OESO Foundation will henceforth render tangible, and directly useful in daily practice, the very specific achievement of a network of excellence bringing together, in each discipline, the most prominent representatives of gastroenterology in the world.