J Neurol Neurosurg Psychiatry 51:1503-1507 doi:10.1136/jnnp.51.12.1503
  • Research Article

Constipation and paradoxical puborectalis contraction in anismus and Parkinson's disease: a dystonic phenomenon?

  1. S E Mathers,
  2. P A Kempster,
  3. M Swash,
  4. A J Lees
  1. Sir Alan Parks Physiology Laboratory, St Mark's Hospital, London, UK.


      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.