so ANO RECTAL ANOMALIES

This description is mainly based on experience gained at Great Ormond Street over the past nine years-about 300 cases having been admitted. It owes much to the teaching of Denis Browne. The classification of Ladd and Gross (I934) into four types has been abandoned because it did not seem to give useful grouping of cases with similar origins, treatment or prognosis. A classification has been developed which is based on different conceptions of the embryology-which were first put forward by Sir Arthur Keith as long ago as I908-and only differs in detail from the usage of Stephens (I953) and Browne (I955). Imperforate anus is an unfortunate generic name because the great majority of cases have some opening even though it be displaced and small. Two concepts seem to explain the majority of abnormalities as clinically found. One is the idea of failure of migration so that an orifice or its remnant will remain at the site of a more primitive anus. The other is the concept of excessive fusion of the lateral genital folds ' covering ' the anus and usually leaving an opening somewhere anterior to the usual anal site. (Bill, of Seattle, has recently (1958) put forward somewhat similar suggestions.) The commoner clinical types found are:-