Imperforate anus is now corrected with substantial success, due to a better understanding of the anatomy and physiology of defecation.1,2 The anomaly is usually recognized promptly, and the surgical procedures for its correction and their timing are well standardized. Experience reveals that considerable morbidity and potential mortality may result from late recognition of the occult anomalies which may accompany imperforate anus. The most dangerous latent anomalies are found in the genitourinary and alimentary tracts. Definition of the frequency of the associated defects was accomplished by study of the last 100 consecutive cases of imperforate anus seen at the University of Michigan Hospital during the 20-year period from 1949 to 1969.
Imperforate anus patients were divided according to the classification of Ladd and Gross.3 Anal or rectal stenosis is termed type 1 imperforate anus, a type 2 anomaly is a persistent proctadeal or posterior cloacal membrane, and anal atresia