Periproctal abscess and anal fistula are common disease in pediatric surgery. During the last 21 years a total 470 cases have been experienced. 463 (98.9%) were male and 7 were female, showing an outstanding predominance in male. Age at time of onset is within three months after birth in about two-thirds of the cases. The lesions were found at the two lateral directions of the anus in 68.5% of cases, while at the anterior or/and posterior direction in 2%. In female cases, about a half occurred at two lateral directions, and the other half occurred at the anterior posterior directions. The cases with birth weight over 3,000g were 91% of all cases, and the patients with birth weight over 3,500 g were 39%. This disease shows the trend of high incidence in the well developed infant. The results of treatment showed that 47 patients were treated by surgery. Fistulotomy was done in 31 cases, while fistulectomy was done in 16 cases. Thirty-six cases (78%) were cured within 30 days and 4cases had repeated surgery. In 120 cases in which the fistula remains unhealed after a period of three months, some characteristic features were presented. Multiple fistulas were apt to remain unhealed. The later the treatment is begun, the cure is more prolonged. Anorectal manometory with perfused side opening catheter was carried out in 12 obstinate cases with conservative treatment. As a result of'the measurement, the decrease of the anal canal resting pressure, the basal rhythmic contraction number of anal and the increase of the rectal resting pressure were recorded. These data may be arised from the damage of internal and external sphincteric muscle. Therefore, in these cases, it may be best to do the surgical procedure.
