sphincteroscopy

sphinc·ter·os·co·py

(sfingk'tĕr-os'kŏ-pē),
Visual examination of a sphincter.

sphincteroscopy

(sfĭngk″tĕr-ŏs′kō-pē)
Inspection of the internal anal sphincter. The internal anal sphincter is covered by anodermal and mucous membrane tissues that cannot be seen unless exposed surgically.