Rectoscopy is the direct instrumental visualization of the rectum; rectosigmoidoscopy is such visualization of both the rectum and the sigmoid flexure of the colon. It is striking, in view of the frequency of intestinal disturbances in infants and children, that a standardized technic of rectosigmoidoscopy, the only procedure available for the direct observation of the rectum and sigmoid flexure, for use with young children and its advantages have not been described in the literature. A survey reveals a few vague references to sporadic efforts to use the procedure, but the data are too general or too brief to be of practical value. When practiced, it was used primarily in older children, probably because of the easier management and simpler instrumentation, and seems to have been restricted to the rectum. The problem with the older child is not unlike that with the adult. However, with the younger child and the infant,