Gastroenterology and the New Millenium

The close of the twentieth century marks approximately one hundred years of progress in gastroenterology since its origins in classic studies of GI physiology by Cannon and others. Looking backward at this threshold, it is possible to recognize that there have been many key advances during that time in both understanding of digestive disease processes and the development of therapeutic interventions. These include elucidation of key physiologic and pathophysiologic processes, identification of some (but not all) causative agents of disease as exemplified by the hepatotrophic viruses and helicobacter pylori, development of endoscopic techniques for diagnosis and treatment and a spectrum of pharmacologic agents as illustrated by the proton pump inhibitors. However, as we move forward into this new century and millenium it is likely that even these impressive and widespread changes in gastroenterology will be surpassed by new changes and discoveries. These include a changing landscape in the spectrum of disease in part due to our own interventions with more definitive therapies and overall socioeconomic development. For example, we will see the eventual decline in prevalence of chronic hepatitis (certainly B) and related hepatocellular carcinoma with the maturation of the effects of prevention through vaccination; H. pylori and associated cancer can be expected to decline as well. These trends may be mirrored by rising frequency of colorectal neoplasia, GERD and here in Japan IBD (predictably, Crohn's will eventually follow the incidence of ulcerative colitis). While the spectrum of disease will evolve we will be able to apply more precise diagnosis and eventually truly definitive therapy for many of the disorders that we now manage with empiric therapies that control manifestations but do not resolve the underlying basis of disease. An especially important dimension of diagnosis will be the definition of the genetic basis of digestive diseases or predisposition to these disorders. Thus the practice of gastroenterology in the future can be expected to encompass genetic diagnosis and with it genetic counseling. Although not axiomatic, it is reasonable to assume that definition of the causes of diseases that so far have eluded us (e.g. IBD) will lead to more effective therapies, ones which are much more selective and thus less confounded by undesirable side effects. In broad terms we can expect that these will include those that are unique to the various receptor subtypes (as agonists or antagonists) that are responsible for regulating GI function including motility, growth, secretion and absorption and blood flow. Their effectiveness will be leveraged by more sophisticated approach to drug administration and monitoring with the availability of implanted “smart” delivery systems that monitor response and modulate dose in real time in parallel with effecting long range telemetry. The link between patient and physician will be at once more intimate as a continuous interaction and at the same time more dissociated. It is likely that whole new approaches to replacement of irreversibly damaged GI organs will transform intervention in end stage disease which may encompass xenotransplantation and bioengineered organs. The practice of gastroenterology will also undergo vigorous evolution in the use of intraluminal im- aging and intervention that may well eclipse our conventional concepts of endoscopy. Imaging outside of the visual spectrum will reveal physiologic alterations in the broadest terms. Further progress in efforts already underway will lead to remote sensors that will navigate the GI tract, ducts and vessels with the physician effecting interventions in the manner that surgeons are already operating at great distances through remote controls. The exciting future for gastroenterology will be realized through the emerging availability of powerful new research tools. The completion of the genome projects, advances in proteonomics, rational drug design all offer enormous promise. New tools in computer science, detectors and micromachines may be equally pivotal. The brave new world of diagnosis and therapeutic interventional options will also come with unprecedented challenges. They will require new and creative approaches to training of physicians who will likely need an even broader spectrum of scales than we currently demand. Most importantly many of these advances will carry with them important and complex ethical issues. While society generally will need to come to grips with the many moral dilemmas that we may only be able to guess at today, it will be critical that the gastroenterologist is prepared to take responsibility for confronting these issues with the commitment to the best care of the patient.