Abstract
The indications of endoscopic ultrasonography (EUS) for diseases of the lower digestive tract include cancers, submucosal tumors, extramural lesions, inflammatory diseases, etc. Ultrasonic endoscopes and miniature probes are available ; the use of miniature ultrasonic probes is generally adequate except for lesions of the lowermost part of the rectum, tumors with considerable thickness, and extramural lesions. Especially, miniature ultrasonic probes are useful for evaluating the depth of early colorectal cancers, which consists of the majority of practice with EUS. Mainly, deaerated water instillation method is employed for observation ; adequate positioning of a patient for immersing a lesion with water and short time examination are important. If the advantages and disdvantages of EUS in various disorders are satisfactorily recognized, the use of EUS will contribute to improving the diagnostic capability.
