imperforate anus

synonym: anal atresia
https://doi.org/10.1351/goldbook.10840

Congenital absence of an anal opening due to the persistence of epithelial plug (persistence of the anal membrane) or to complete absence of the anal canal.

Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 767 [Terms] [Paper]