Anal fistula, simple, initial

This code describes an initial encounter for a simple anal fistula, which is an abnormal, chronic tract connecting the anal canal or rectum to the perianal skin. A simple fistula typically involves a single, straight tract with a low opening and no significant branching or involvement of the sphincter muscle.

Use this code for a patient presenting for the first time with a newly diagnosed, uncomplicated anal fistula. Documentation should clearly indicate the "initial" nature of the encounter and describe the fistula as "simple" based on clinical assessment or imaging findings.

• Ensure documentation specifies "initial encounter" for this code; subsequent encounters for the same simple fistula would use a different seventh character.
• Distinguish between simple and complex anal fistulas; complex fistulas (e.g., high, multiple tracts, recurrent) have different code assignments.
• Do not use this code for perianal abscess without a confirmed fistulous tract.