<unk>  is a disorder of the hymen, characterized by a rigid hymen and<unk>  introitus, whether acquired or congenital. It excludes an imperforate hymen. The condition can be relieved by outpatient surgery or manual dilation.
Tight hymenal ring
Kock pouch
Terminal web
Cecal bascule
Nodule of vermis
Limbal ring
Posterior perforated substance
Infundibulum