The millennium provides an opportunity to contemplate and review the recent past and to plan for the future. The last half century, in particular, has been the golden age of gastroenterology, wherein rigorous, scientifically based medicine has revolutionized gastrointestinal diagnosis and therapy. The technologic fantasy and science fiction of 50 years ago has become the real and commonplace. The peptic ulcer that was treated by the Sippy meal, gastric freezing, or gastric radiation 50 years ago is now treated by scientifically based pharmacotherapy, including potent proton-pump inhibitors and antimicrobial therapy. The cecal adenoma that required inpatient laparotomy and colotomy for polypectomy 30 years ago is now simply removed by ambulatory colonoscopic polypectomy. The surgical gastrostomy for long-term enteral feeding of 20 years ago is replaced by percutaneous endoscopic gastrostomy. The awkward, painful, and sometimes dangerous semiflexible endoscope of 42 years ago has been replaced by the simple, convenient, and safe flexible endoscope. The word abdomen is derived from the Latin abdere , meaning hidden or concealed. 62 The flexible endoscope, the computed tomography (CT) scan, and the abdominal ultrasound study have opened this previously inaccessible organ to observation and inspection by the gastroenterologist, radiologist, and surgeon without surgery. The surgeon's knife has become the endoscopist's papillotome, and the laparotomy has become a laparoscopy. The diagnostic laparotomy has become nearly obsolete. The excitement at novel discoveries yields to complacency with time as the inconceivable becomes ubiquitous. Yet what human endeavor has contributed more to the betterment of humanity than medicine? For example, one simple gastroenterologic therapy—oral rehydration with glucose and electrolyte solution—has saved millions of lives per year worldwide from cholera. This revolution was accomplished not by the sword but by the pencil, not by rhetoric but by statistics, and not by climbing the ramparts but by toiling in the laboratory and clinic. This revolution is largely undocumented, unrecognized, and unpraised. The furious pace of magnificent discovery and invention and the preoccupation of the discoverers and inventors with discovery and invention have left little time for writing a history. A gastroenterologic history provides manifold salutary effects. First, individuals who toiled, created, and invented receive overdue and well-deserved recognition. Second, a history provides role models to the initiate or student in gastroenterology. Third, a historical perspective provides the discipline an identity, purpose, and mission. Fourth, a history collates, categorizes, and clarifies the important issues in gastroenterology. An historical perspective helps outline important ongoing areas of controversy and research interest and suggests strategies, approaches, and techniques for further research. Fifth, a history that celebrates great past gastroenterologic achievements may cause legislators to reconsider draconian cutbacks in funding future worthy projects. A contemporaneous history is most meaningful because a contemporary can evaluate the impact of changes, with knowledge of past and present. Immediacy provides impact. This article is included in this issue of the Gastroenterology Clinics in honor of the millennium. To provide a proper perspective, Cappell asked several senior luminaries to vote as a committee on the 50 great landmarks during the past 50 years. The vote revealed surprising concordance, with the largest discrepancy being a difference in six of the selected landmarks. The importance and history of each landmark discovery is discussed to provide an appropriate vehicle for a brief modern history of gastroenterology. The first part of this historical essay, which discussed endoscopic, radiologic, and surgical techniques and upper gastrointestinal disorders, was presented in the March 2000 issue of the Gastroenterology Clinics . This second part completes the historical essay.