Hereditary vacuolar internal anal sphincter myopathy causing proctalgia fugax and constipation: a new case contribution.

Hereditary anal sphincter myopathy is rare. We present a family with one affected member with proctalgia fugax, constipation and internal anal sphincter hypertrophy. Ultrastructural findings show vacuolization of smooth muscle cells without the characteristic polyglucosan inclusion. Further relief of symptoms was obtained using an oral calcium antagonist. Based on clinical presentation, endosonography and morphological findings, we consider our case is a histological variant of the vacuolar myopathy originally described.