Rectal fistula, simple, persistent

This code signifies a simple, persistent abnormal tract connecting the rectum to another surface, typically the perianal skin. A simple fistula is characterized by a single, straight tract without branching or associated abscesses, and "persistent" indicates it has not resolved spontaneously.

Assign this code when documentation clearly identifies a rectal fistula as simple and chronic or long-standing. This typically involves a physical exam noting a single external opening and a probe demonstrating a straight, non-complex tract, or a history indicating failed conservative management.

• Differentiate from complex rectal fistulas (e.g., multiple tracts, involvement of sphincter muscle, recurrent) which are coded elsewhere.
• Ensure documentation specifies "persistent" or a similar term indicating chronicity; otherwise, consider an unspecified or acute code if no persistence is noted.
• Do not code an associated abscess separately if it is an integral part of the simple fistula formation.