Anorectal malformation (ARM) refers to a group of congenital defects characterized by the absence, incomplete development, or abnormal positioning of the anus and rectum. These defects affect the normal passage of stool due to a missing or misplaced anal opening and may be associated with abnormal connections (fistulas) between the rectum and the urinary or genital tracts.
Detailed Definition
Anorectal malformations are congenital anomalies occurring during fetal development in which the normal formation of the anus, rectum, and sometimes the distal colon is disrupted. This results in either:
- No visible anal opening on the perineum (imperforate anus), or
- An anal opening that is misplaced, narrowed, or connected abnormally to the urinary or genital systems through fistulas.
Key Points
- ARM can range from mild forms (e.g., small anal stenosis) to severe complex malformations (e.g., cloacal malformations).
- It affects both male and female newborns.
- ARM may be isolated or occur along with other congenital anomalies, such as in the VACTERL association (Vertebral, Anorectal, Cardiac, Tracheoesophageal, Renal, and Limb anomalies).
- Early diagnosis and management are important to restore normal bowel function and prevent complications.
Summary Definition
Anorectal malformation is a congenital defect in which the anus and rectum fail to develop normally, leading to absent or misplaced anal opening and often abnormal fistulous connections with the urinary or genital tracts, resulting in impaired defecation.