Pediatric hernia is caused by the formation of a canal (hernia sac) in the inguinal cavity due to non-atresia or incomplete atresia of the sphincter protrusion formed by the testis descending into the scrotum during embryonic development, resulting in the intestinal canal or omentum entering the hernia sac in the abdominal cavity, which is usually a hiatal hernia if it can enter the scrotum and a straight hernia if it does not enter the scrotum.