external anal sphincter
a fusiform ring of striated muscular fibers surrounding the anus, attached posteriorly to the coccyx and anteriorly to the central tendon of the perineum; it is subdivided, often indistinctly, into a subcutaneous part, a superficial part, and a deep part for descriptive purposes.
Synonym(s): musculus sphincter ani externusTA, external sphincter muscle of anus
Search Stedman's Medical Dictionary
Examples: glitazone, GI cocktail, etc.