Document Detail


Study of the role of the second defecation reflex: anorectal excitatory reflex in the pathogenesis of constipation.
MedLine Citation:
PMID:  12742205     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Previous studies have shown that anal distension caused rectal contraction, an action mediated through the anorectal excitatory reflex. Anal anesthetization aborted rectal contraction and rectal evacuation was induced by excessive straining. We investigated the hypothesis that inhibition or absence of the anorectal excitatory reflex could lead to constipation. METHODS: We studied 18 patients (mean age +/- SD: 40.6 +/- 5.8 years, 14 women) with rectal inertia, 14 (41.7 +/- 6.6 years, 12 women) with puborectalis paradoxical syndrome, and 10 healthy volunteers (37.9 +/- 4.8 years, 8 women). The rectum was filled with normal saline until urge and then evacuated; residual fluid was calculated. The anal and rectal pressure response to anal balloon distension in increments of 2 mL of saline was recorded by a two-channel microtip catheter. RESULTS: In the healthy volunteers, saline was evacuated as a continuous stream without straining except occasionally at the start of evacuation; no residual fluid was encountered. Anal balloon distension effected notable rectal pressure increase. In rectal inertia patients, evacuation occurred in small fluid gushes produced with excessive straining; residual fluid of large volume was collected. Anal balloon distension up to 10 mL produced no notable rectal pressure changes. The patients with PPS failed to evacuate more than a few mL of fluid despite excessive straining; the volume of residual fluid was considerable. Anal balloon distension caused a notable rectal pressure rise. The results were reproducible. CONCLUSIONS: These results suggest that the defecation reflexes (rectoanal and anorectal) are absent in rectal inertia patients and this presumably denotes a neurogenic disorder. The anorectal reflex is active in puborectalis paradoxical syndrome, but the rectoanal reflex is not, indicating a possible myogenic defect in the puborectalis muscle.
Authors:
Ahmed Shafik; Ali A Shafik; Olfat El-Sibai; Ismail Ahmed
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of the American College of Surgeons     Volume:  196     ISSN:  1072-7515     ISO Abbreviation:  J. Am. Coll. Surg.     Publication Date:  2003 May 
Date Detail:
Created Date:  2003-05-13     Completed Date:  2003-06-02     Revised Date:  2005-11-17    
Medline Journal Info:
Nlm Unique ID:  9431305     Medline TA:  J Am Coll Surg     Country:  United States    
Other Details:
Languages:  eng     Pagination:  729-34     Citation Subset:  AIM; IM    
Affiliation:
Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Cairo, Egypt.
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MeSH Terms
Descriptor/Qualifier:
Adult
Anal Canal / innervation*
Balloon Dilatation
Constipation / etiology*,  physiopathology
Defecation / physiology*
Female
Humans
Male
Pressure
Rectum / innervation*
Reflex / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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