2018 Volume 54 Issue 6 Pages 1240-1244
We present a case of anterior perineal anus with anal stenosis presenting as intractable constipation. The patient was a 6-year-old girl, whose normally appearing anus was stenotic and anteriorly located (anal position index, 0.33). Radiological examinations showed that the posterior wall of the rectum appeared like a shelf, and an examination with electrical stimulations revealed that the anus was circumferentially surrounded by external anal sphincter muscle. On the basis of these findings, anterior perineal anus with anal stenosis was diagnosed, and an operation was performed under general anesthesia. The anus was shifted posteriorly by transverse incision and longitudinal closure of the perineal skin. Anoplasty with posterior internal sphincterectomy was then performed to form an adequate anal opening. Postoperatively, anal stenosis was resolved and the patient achieved daily bowel movement, although the result of the posterior anal shift was unsatisfactory. Histopathological examination showed atrophy and fibrosis of the internal anal sphincter muscle, which suggested that these changes might be related to the development of anterior perineal anus with anal stenosis.
