Abstract
Functional radiological examinations of rectum and anal canal before and during defecation were performed using a video-tape recorder system in 20 children with normal defecation aged 2 months to 14 years old. Following results were obtained. 1. Rectal sensation was mesured by means of the amount of 150% Barium sulfate injected into the rectum. The average amount was 100ml (40-150ml) in 10 infants aged 4 years to 11 years old. There were no correlation between the age and the amount of Barium in these ages. 2. The anterior wall of anorectum protruded softly in girls and became remarkable in older age. 3. At resting state, the anorectal angulation became sharp by age, and it reached at same level (60°-90°) after 5 or 6 years old. 4. By squeezing anal sphincter muscles, the length of the anal canal became 1.2-1.5 times longer than that of resting state. 5. Two types of defecation were observed, one was reflex type and another was straining type. Reflex type of defecation, which was mainly observed in younger age group, was followed by the contruction of the rectum. Straining type of defecation, which was mainly observed in older age group, was accomplished by abdominal pressure of straining. 6. In normal fedecation, no leakage of Barium was observed throughout the injection and resting period. These results will make it reasonable and clear to assess postoperative problems of defection radiologically.
