<unk>  is a type of medical investigation which images the structures of the anal canal. It is used in the investigation of some anorectal symptoms, e.g. fecal incontinence or obstructed defecation.
Endoanal ultrasound
Anorectal manometry
Rectal examination
Pouchoscopy
Endorectal coil magnetic resonance imaging
Transrectal ultrasonography
Vaginoscopy
Dry enema