Anorectal Testing

Karthik Ravi, Adil E. Bharucha

Research output: Chapter in Book/Report/Conference proceedingChapter


Anal manometry and a rectal balloon expulsion test, occasionally supplemented by defecography, are necessary for diagnosing functional defecatory disorders. Diagnostic testing is also useful for evaluating the pathophysiology and guiding management in fecal incontinence. Anal resting and squeeze pressures measured by manometry reflect predominantly internal and external anal sphincter function respectively. Disordered defecation is diagnosed by assessing rectal balloon expulsion and the recto-anal pressure gradient during simulated evacuation. Endoanal ultrasound and magnetic resonance imaging (MRI) visualize anal sphincter defects, scars, and atrophy. Both tests are comparable for the internal sphincter but only MRI identifies external sphincter atrophy. Barium defecography can characterize rectal evacuation and pelvic floor function and thereby reveal evacuation disorders, excessive perineal descent, and rectocoeles. Dynamic MRI provides similar information and also images the bladder and genital organs. Since the measurement of pudendal nerve latencies suffers from several limitations, anal sphincter electromyography is recommended when neurogenic sphincter weakness is suspected.

Original languageEnglish (US)
Title of host publicationPractical Gastroenterology and Hepatology
Subtitle of host publicationSmall and Large Intestine and Pancreas
Number of pages9
ISBN (Print)9781405182744
StatePublished - Aug 31 2010


  • Anorectal manometry
  • Anorectal testing
  • Defecography
  • Endoanal ultrasound
  • Pelvic MRI

ASJC Scopus subject areas

  • Medicine(all)


Dive into the research topics of 'Anorectal Testing'. Together they form a unique fingerprint.

Cite this