pelvic floor dyssynergia

Last reviewed 12/2021

• pelvic floor dyssynergia
  • characterised by paradoxical contraction or failure to relax the pelvic floor during attempts to defecate
    • frequently associated with symptoms of difficult defecation including feeling of incomplete evacuation after defecation, straining, and digital facilitation of defecation
  • prevalence is unknown
    • note however, in patients referred for evaluation of chronic constipation, pelvic floor dyssynergia is found in 25-50% of both children and adults
      • may be an overestimation due to the high false-positive rates seen in some studies
  • pathophysiology
    • this condition is not attributable to a neurological lesion as at least two-thirds of patients can learn to relax the external anal sphincter and puborectalis muscles appropriately when provided with biofeedback training
    • anxiety and/or psychological stress may contribute to the development of pelvic floor dyssynergia by increasing skeletal muscle tension
      • adults with difficult defecation have exhibited significantly higher scores for anxiety, depression, interpersonal sensitivity, obsessive compulsive traits, phobic anxiety, and somatization
    • pelvic floor dyssynergia is more common in women with a history of sexual abuse (1)
  • diagnosis

    (1) patient must satisfy diagnostic criteria for functional constipation;

    (diagnostic criteria for functional constipation are: at least 12 weeks (which need not be consecutive) in the preceding 12 months of two or more of: (1) straining in >1/4 defecations;(2) lumpy or hard stools in >1/4 defecations; (3) sensation of incomplete evacuation in >1/4 defecations; (4) sensation of anorectal obstruction/blockage in >1/4 defecations; (5) manual maneuvers to facilitate >1/4 defecations (e.g., digital evacuation, support of the pelvic floor); and/or (6) <3 defecations/week. Loose stools are not present, and there is insufficient evidence for irritable bowel syndrome)

    (2) must be manometric, EMG, or radiologic evidence for inappropriate contraction or failure to relax the pelvic floor muscles during repeated attempts to defecate;

    (3) must be evidence of adequate propulsive forces during attempts to defecate;

    and (4) must be evidence of incomplete evacuation

  • clinical evaluation
    • physiological investigations considered useful for making a diagnosis of pelvic floor dyssynergia are: (1) anorectal manometry, (2) electromyography of the external anal sphincter, (3) balloon defecation (simulated defecation), and (4) defecography
    • the clinical finding, on physical examination, that the patient is able to decrease anal canal pressure when straining is useful for ruling out pelvic floor dyssynergia, but an increase in anal canal pressure when straining during physical examination is not a reliable indication of the presence of pelvic floor dyssynergia
  • management
    • two types of training have been described for pelvic floor dyssynergia:

      (1) biofeedback training in which sensors in the anal canal or adjacent to the anus, monitor and provide feedback to the patient on striated muscle activity or anal canal pressures;

      (2) simulated defecation in which the patient practices defecation of a simulated stool

      • both of these interventions seem to be effective - there is a reported overall an overall success rate of 67%

Reference:

1. Whitehead WE et al.Functional disorders of the anus and rectum. Gut. 1999 Sep;45 Suppl 2:II55-9.