A clinical data base system was developed that integrates gastrointestinal radiologic examinations, endoscopic studies, and pathologic diagnoses. An interrogative language is used, so that data input occurs by response to a series of relevant questions and answers that are constructed by the clinical staff without programmer support. Data are stored in a hierarchical, natural-language (noncoded) format, making them easily understandable by all clinical groups. Since the computer system is interactive, there are on-line capabilities for data input at various times as well as for instantaneous retrieval of all data on a given patient. Retrieval (search) of data uses Boolean logic, allowing for intercorrelative studies among radiology, endoscopy, and pathology. Data can then be isolated in files in which the computer can generate demographic and statistical data by use of a series of programs. Both data search and analysis can be accomplished without programming knowledge. Not only are research functions served by the system, but educational functions such as preparation of conferences and lectures, professional quality assurance, and resident teaching through follow-up and missed-case review can be performed.