Endoscopy has revolutionized clinical gastroenterology. In 1961 Basil Hirschowitz published the first flexible endoscopic examination of the stomach and duodenal bulb. We moved from flexible fiberendoscopes to current video-endoscopic equip ment. Current video-endoscopes incorporate a black and white or color 'chip' at the tip of the instrument which transforms the visual image into electronic signals. The size of the pincet is constantly getting smaller, heading for 5 /Lm, further increasing the resolution. The signals are reassembled into high-quality color images in a video monitor. Endoscopes are now used to examine the entire gastrointestinal tract from esophagus to rectum, including the biliary and pancreatic ductal system. Targeted endoscopic biopsy offers rapid and precise diagnosis. Endoscopic ultrasonography is of unsurpassed accuracy in staging gastrointestinal tumors, in assessing pancreatic and biliary disease, and disorders of the rectum and anal canal. Moreover, targeted cytological sampling is possible of abnormalities of the intestinal wall or peri intestinal lymph node. Yet despite these glamorous achievements changes are to be expected in the overall emphasis of diagnostic endoscopy. Magnetic resonance cholangiopancreatography may very well compete for a substantial fraction of diagnostic ERCP. Virtual colonoscopy or computed tomographic colography may well compete with (and take over?) screening/surveillance colonoscopy."

IS CROHN'S DISEASE A MYCOBACTERIAL DISEASE'! The fact that the differential diagnosis of inflammatory bowel disease includes intestinal infections has been a source of much interest and clinical concern for many years. Since the recognition of ulcerative colitis and Crohn's disease as clinical entities, numerous attempts have been made to identify a specific organism resulting in the clinical and pathologic picture of Inflammatory Bowel Disease. The first suggestion about a connection between Johne's disease, a chronic mycobacterial enteritis in cattle, and Crohn' s disease occurred in 1913, when Dalziel described enteritis in humans which, although resembling intestinal tuberculosis, he believed to be a new disorder. Since the work of Crohn in the thirties a few investigators attempted to look for mycobacteria in Crohn's disease. Until now the work of Van Patter, Burnham and others did not receive widespread recognition. In 1984 the isolation of M. paratuberculosis was reported by Chiodini et al. This report initiated the current interest and controversy about a mycobacterial etiology in Crohn's disease. The hypothesis "Crohn's disease is Johne's disease" did not receive widespread recognition, but has lead to the first muIticentered efforts to determine whether or not mycobacteria are associated with Crohn's disease.

IS CROHN'S DISEASE A MYCOBACTERIAL DISEASE'! The fact that the differential diagnosis of inflammatory bowel disease includes intestinal infections has been a source of much interest and clinical concern for many years. Since the recognition of ulcerative colitis and Crohn's disease as clinical entities, numerous attempts have been made to identify a specific organism resulting in the clinical and pathologic picture of Inflammatory Bowel Disease. The first suggestion about a connection between Johne's disease, a chronic mycobacterial enteritis in cattle, and Crohn' s disease occurred in 1913, when Dalziel described enteritis in humans which, although resembling intestinal tuberculosis, he believed to be a new disorder. Since the work of Crohn in the thirties a few investigators attempted to look for mycobacteria in Crohn's disease. Until now the work of Van Patter, Burnham and others did not receive widespread recognition. In 1984 the isolation of M. paratuberculosis was reported by Chiodini et al. This report initiated the current interest and controversy about a mycobacterial etiology in Crohn's disease. The hypothesis "Crohn's disease is Johne's disease" did not receive widespread recognition, but has lead to the first muIticentered efforts to determine whether or not mycobacteria are associated with Crohn's disease.

Endoscopy has revolutionized clinical gastroenterology. In 1961 Basil Hirschowitz published the first flexible endoscopic examination of the stomach and duodenal bulb. We moved from flexible fiberendoscopes to current video-endoscopic equip ment. Current video-endoscopes incorporate a black and white or color 'chip' at the tip of the instrument which transforms the visual image into electronic signals. The size of the pincet is constantly getting smaller, heading for 5 /Lm, further increasing the resolution. The signals are reassembled into high-quality color images in a video monitor. Endoscopes are now used to examine the entire gastrointestinal tract from esophagus to rectum, including the biliary and pancreatic ductal system. Targeted endoscopic biopsy offers rapid and precise diagnosis. Endoscopic ultrasonography is of unsurpassed accuracy in staging gastrointestinal tumors, in assessing pancreatic and biliary disease, and disorders of the rectum and anal canal. Moreover, targeted cytological sampling is possible of abnormalities of the intestinal wall or peri intestinal lymph node. Yet despite these glamorous achievements changes are to be expected in the overall emphasis of diagnostic endoscopy. Magnetic resonance cholangiopancreatography may very well compete for a substantial fraction of diagnostic ERCP. Virtual colonoscopy or computed tomographic colography may well compete with (and take over?) screening/surveillance colonoscopy.