A linguistic analysis of the narrative which appears in patient documents, in the domain of urology, has shown that the information is conveyed by a small number of semantic statement types composed of syntactic combinations of medical and English word classes. It has been shown that words from different classes occurring in the diagnosis for the patient disease follow some regular grammatical rules. This impressive linguistic regularity in clinical narrative has made it encouraging to develop a recognizer which is capable of recognizing disease diagnosis in the narrative clinical documents in the domain of urology. The recognizer was implemented using the C language. This recognizer output information which could be refined to a form suitable for management by a database management system for further computerized information processing.