ICD-10-CM > K00-K95 > K55-K64 > K60 > K60.3 > K60.31 K60.31 Anal fistula, simple Non-Billable/Non-Specific Applicable To Low intersphincteric anal fistulaSuperficial anal fistula Codes K60.311Anal fistula, simple, initialK60.312Anal fistula, simple, persistentK60.313Anal fistula, simple, recurrentK60.319Anal fistula, simple, unspecified