Congenital absence, atresia and stenosis of anus w fistula

This code describes a birth defect where the anus is either completely missing (absence), abnormally closed (atresia), or severely narrowed (stenosis), and is accompanied by an abnormal connection (fistula) between the rectum and another organ or the skin. This condition prevents normal passage of stool and often requires surgical intervention.

Assign this code for neonates or infants diagnosed with an imperforate anus that also presents with a rectourinary, rectovaginal, rectoperineal, or other type of fistula. Documentation must clearly specify both the anal anomaly and the presence of a fistula. This code is typically used for the initial diagnosis and subsequent follow-up of this specific congenital malformation.

• Differentiate from Q42.0-Q42.1 (absence, atresia, stenosis of anus without fistula) and Q42.3 (absence, atresia, stenosis of rectum with fistula) based on the primary site and presence/absence of a fistula.
• Always review operative reports and imaging studies to confirm the exact anatomical defect and the presence and type of fistula.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter, especially for surgical repair.