Hereditary internal anal sphincter myopathy causing proctalgia fugax and constipation. A newly identified condition.

Abstract

A newly identified myopathy of the internal anal sphincter is described. In the affected family, at least one member from each of five generations had severe proctalgia fugax; onset was usually in the third to fifth decades of life. Three members of the family have been studied in detail. Each had severe pain intermittently during the day and hourly during the night. Constipation was an associated symptom, in particular difficulty with rectal evacuation. Clinically the internal anal sphincter was thickened and of decreased compliance. The maximum anal canal pressure was usually increased with marked ultraslow wave activity. Anal endosonography confirmed a grossly thickened internal anal sphi..