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Sampling reflex: pathogenic role in functional defecation disorder.

F Pucciani1, M Trafeli2

  • 1Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, 50134, Firenze, Florence, Italy. filippo.pucciani@unifi.it.

Techniques in Coloproctology
|February 15, 2021
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Summary
This summary is machine-generated.

The sampling reflex, crucial for defecation, is impaired in most patients with functional defecation disorder (FDD). This study reveals altered rectoanal inhibitory and excitatory reflexes in FDD, offering insights into obstructed defecation.

Keywords:
Anorectal manometryFunctional defecation disorderObstructed defecationRAERRAIRSampling reflex

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Area of Science:

  • Gastroenterology
  • Physiology
  • Colorectal Surgery

Background:

  • The sampling reflex initiates defecation by coordinating internal and external anal sphincter responses.
  • It involves the rectoanal inhibitory reflex (RAIR) and rectoanal excitatory reflex (RAER).
  • Functional defecation disorder (FDD) is characterized by difficulties in defecation.

Purpose of the Study:

  • To evaluate the integrity of the sampling reflex in patients diagnosed with functional defecation disorder (FDD).
  • To investigate the specific components of the rectoanal inhibitory reflex (RAIR) and rectoanal excitatory reflex (RAER) in FDD.
  • To correlate manometric findings of the sampling reflex with clinical and defecographic parameters in FDD.

Main Methods:

  • A prospective cohort study involving 58 FDD patients and 20 controls.
  • Anorectal manometry was used to quantitatively assess RAIR and RAER.
  • Defecography was performed to evaluate anorectal angle and puborectalis indentation.

Main Results:

  • 86.2% of FDD patients exhibited an altered sampling reflex, characterized by impaired RAIR and exaggerated RAER.
  • Significant correlations were found between positive straining tests, defecographic findings, and specific quantitative measures of RAIR and RAER.
  • Maximal amplitude relaxation and contraction, along with RAIR and RAER durations, showed high sensitivity and specificity in detecting reflex impairments.

Conclusions:

  • The sampling reflex is demonstrably impaired in individuals with functional defecation disorder (FDD).
  • These findings enhance our understanding of the underlying pathophysiology of obstructed defecation in FDD.
  • Targeting the sampling reflex may offer new therapeutic avenues for FDD.