title: Constipation and paradoxical puborectalis contraction in anismus and Parkinson's disease: a dystonic phenomenon?
abstract: Anismus, or constipation due to functional obstruction at the pelvic outlet by paradoxical contraction of the striated sphincter muscles during defaecation straining, is described in ten constipated patients and four patients with Parkinson's disease and constipation. The dysfunctional pattern of muscle recruitment resembled that characteristic of dystonia elsewhere in the body and was indistinguishable in patients with idiopathic anismus and those with extrapyramidal motor disturbance due to Parkinson's disease. These findings suggest that anismus may be a focal dystonic phenomenon.
authors.affiliation: Sir Alan Parks Physiology Laboratory, St Mark's Hospital, London, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Mathers
authors.forename: P A
authors.initials: PA
authors.lastname: Kempster
authors.forename: M
authors.initials: M
authors.lastname: Swash
authors.forename: A J
authors.initials: AJ
authors.lastname: Lees
mesh_terms: D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000503:physiopathology; D003248:Constipation / Q000503:physiopathology*; D004421:Dystonia / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D010300:Parkinson Disease / Q000503:physiopathology*; D012007:Rectum / Q000503:physiopathology*