title: Fecal incontinence in systemic sclerosis is secondary to neuropathy.
abstract: OBJECTIVE
  Systemic sclerosis (SSc) is a chronic multi-system autoimmune disorder with gastrointestinal tract (GIT) involvement in up to 90% of patients and anorectal involvement occurs in up to 50% of patients. The pathogenesis of gastrointestinal abnormalities may be both myogenic and neurogenic. We aimed to identify which anorectal physiological abnormalities correlate with clinical symptoms and thus understand the pathophysiology of anorectal involvement in SSc.
  
  
  METHODS
  In total, 44 SSc patients (24 symptomatic (Sx) (fecal incontinence) and 20 asymptomatic (ASx)) and 20 incontinent controls (ICs) were studied. Patients underwent anorectal manometry, rectal mucosal blood flow (RMBF), rectal compliance (barostat), and rectoanal inhibitory reflex assessment (RAIR).
  
  
  RESULTS
  Anal squeeze pressure was lower in the IC group compared with both the ASx and Sx groups (IC: 46.95 (30-63.9)) vs. ASx: 104.6 (81-128.3) vs. (Sx: 121.4 (101.3-141.6); P < 0.05). Resting pressure was lower in the IC group. RMBF and rectal compliance did not differ between groups. Anal, but not rectal, sensory threshold, was significantly attenuated in Sx patients (Sx: 10.4 (8.8-11.4) vs. ASx: 6.7 (5.7-7.7) vs. IC: 8.5 (6.5-10.4); P < 0.05). There was a positive correlation between anal sensory thresholds and incontinence score in SSc patients (r = 0.54; P < 0.05). RAIR was absent in 11/24 Sx patients but only in 2/20 ASx and in 1/20 IC patients.
  
  
  CONCLUSIONS
  Fecal incontinence in SSc is related to neuropathy as suggested by absent RAIR and higher anal sensory threshold and is related less so to sphincter atrophy and rectal fibrosis.
authors.affiliation: GI Physiology Unit, University College London Hospital, London, UK. norathoua@hotmail.com
authors.forename: Nora M
authors.initials: NM
authors.lastname: Thoua
authors.forename: Mostafa
authors.initials: M
authors.lastname: Abdel-Halim
authors.forename: Alastair
authors.initials: A
authors.lastname: Forbes
authors.forename: Chris P
authors.initials: CP
authors.lastname: Denton
authors.forename: Anton V
authors.initials: AV
authors.lastname: Emmanuel
mesh_terms: D000368:Aged; D001003:Anal Canal / Q000503:physiopathology*; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005242:Fecal Incontinence / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011312:Pressure; D012007:Rectum / Q000503:physiopathology*; D012020:Reflex, Abdominal / Q000502:physiology; D012039:Regional Blood Flow; D012595:Scleroderma, Systemic / Q000150:complications* / Q000503:physiopathology*; D012684:Sensory Thresholds; D018709:Statistics, Nonparametric