title: Diagnostic testing for dyssynergic defecation in chronic constipation: meta-analysis.
abstract: BACKGROUND
  Dyssynergic defecation (DD) results from inadequate relaxation of the pelvic floor on attempted defecation. The prevalence of DD in patients with chronic constipation (CC) is not certain. Aims of this study are to estimate the prevalence of abnormal findings associated with DD across testing modalities in patients referred for physiological testing for CC.
  
  
  METHODS
  Systematic search of MEDLINE, EMBASE and PUBMED databases were conducted. We included full manuscripts reporting DD prevalence in CC, and specific findings at pelvic floor diagnostic tests. Random effects models were used to calculate pooled DD prevalences (with 95% CI) according to individual tests and specific findings.
  
  
  RESULTS
  A total of 79 studies on 7581 CC patients were included. The median prevalence of any single abnormal finding associated with DD was 37.2%, ranging from 14.9% (95% CI 7.9-26.3) for absent opening of the anorectal angle (ARA) on defecography to 52.9% (95% CI 44.3-61.3) for a dyssynergic pattern on ultrasound. The prevalence of a dyssynergic pattern on manometry was 47.7% (95% CI 39.5-56.1). The prevalence of DD was similar across specialty and geographic area as well as when restricting to studies using Rome criteria to define constipation.
  
  
  CONCLUSIONS
  Dyssynergic defecation is highly prevalent in CC and is commonly detected across testing modalities, type of patient referred, and geographical regions. We believe that the lower prevalence of findings associated with DD by defecography supports use of manometry and balloon expulsion testing as an initial evaluation for CC.
authors: Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA. videlock@gmail.com
authors: E J
authors: EJ
authors: Videlock
authors: A
authors: A
authors: Lembo
authors: F
authors: F
authors: Cremonini
mesh_terms: D001259:Ataxia / Q000175:diagnosis* / Q000503:physiopathology; D003248:Constipation / Q000175:diagnosis* / Q000503:physiopathology; D003672:Defecation / Q000502:physiology*; D019841:Defecography; D006801:Humans; D008365:Manometry; D017773:Pelvic Floor / Q000503:physiopathology*