Imperforate Anus (IA)

Initial diagnosis is usually made during the first physical examination after birth. IA can often be identified by inspecting the perineum. The condition is classified as either high-type or low-type IA based on the position of the rectum relative to the pelvic muscles and the presence of a fistula.

In male infants, high-type IA is more common and often presents with more severe symptoms, whereas female infants are more likely to have low-type IA, which tends to be less severe.

Further evaluation, including abdominal ultrasound, spinal and sacral X-rays, and echocardiography, is performed to assess for associated anomalies.

IA is not typically a surgical emergency. The initial management involves assessing whether immediate colostomy is necessary, and determining if urgent treatment is required for any coexisting urologic or systemic anomalies.

In high-type IA, a colostomy is usually performed first to relieve bowel obstruction as a temporary measure. A colostomy is a surgical procedure that creates an opening in the abdominal wall, where a part of the colon (large intestine) is brought to the surface to form a stoma. Definitive treatment involves anorectoplasty, which surgically creates a new anus in the correct position. Most patients undergo posterior sagittal anorectoplasty (PSARP), though some may require a combined abdominal and posterior sagittal approach.

In low-type IA with a visible perineal fistula, a primary anoplasty may be performed without the need for a protective colostomy.