Anal Canal Duplication in a 25-Year-Old Female Patient.

Anal canal duplication (ACD) is a congenital malformation that typically presents and is diagnosed early in life. It can be associated with other syndromes or congenital malformations. ACD is one of the rarest duplications of the gastrointestinal tract, with no more than 90 to 100 cases reported in the literature. It can be confused with more frequent pathologies such as perianal fistula, especially when it occurs in adulthood. We present the case of a 25-year-old female patient who presents with a second orifice above the native anal orifice. An arthroscopic examination was performed, an incidental diagnosis of ACD was made, and a complete excision of the duplicated anal canal was performed. The aim of the study is to expand the information on this rare pathology in order to take it into account as a differential diagnosis in patients with abscesses, recurrent fistulous tracts, or any other anorectal pathology.