Diagnostic disagreement between tests of evacuatory function: a prospective study of 100 constipated patients

Abstract

There is considerable disagreement between the results of various tests used to diagnose ED and FDD. This highlights the need for a reappraisal of both diagnostic criteria, and what represents the 'gold standard' investigation.

Normal values for assessment of anal sphincter morphology, anorectal motion, and pelvic organ prolapse with MRI in healthy women

“…In this study, 10% or fewer women had descent of the bladder base or uterus for 4 cm or more below the pubococcygeal line or a rectocele measuring 4 cm or larger, which suggests that this cutoff is useful for identifying pathological descent or rectoceles. However, even smaller rectoceles may cause symptoms, particularly if they do not empty during defecation …”

High-resolution Anorectal Manometry for Identifying Defecatory Disorders and Rectal Structural Abnormalities in Women

“…4, 10 Taken at the extreme, these observations undermine the concept that rectoanal discoordination is responsible for defecatory disorders. Offsetting those concerns, rectal evacuation assessments with anorectal HRM, BET, and MRI were significantly correlated in this study, which substantiates the criterion validity of these tests.…”

“…7 The agreement between balloon expulsion and barium defecography is fair and between water perfused anorectal manometry and defecography is poor. 10 Prompted by these observations, the Rome IV criteria recommend at least two abnormal anorectal tests for diagnosing defecatory disorders in constipated patients. 1 These findings also potentially undermine the diagnostic utility of these tests.…”

Review article: dyssynergic defaecation and biofeedback therapy in the pathophysiology and management of functional constipation

“…Frustratingly, however there is no gold standard diagnostic modality for confirming dyssynergic defaecation in patients with chronic constipation. There is also evidence of disparity in results when evaluating between modalities and with each in isolation . Given this, a diagnosis of dyssynergia requires two dynamic tests to be positive including impaired evacuation on balloon expulsion test or defaecography, inappropriate contraction of the pelvic floor muscles or incomplete relaxation of the anal sphincter on anorectal manometry, anal surface electromyography or imaging studies (Figure ) …”

“…Anorectal manometry indirectly assesses anorectal function by measuring recto‐anal pressures and motor coordination . It evaluates: (1) anal sphincter function (2) recto‐anal reflex activity and (3) changes in anal and rectal pressures during simulated defaecation .…”