ICD-10-CM > K00-K95 > K55-K64 > K60 > K60.3 K60.3 Anal fistula Non-Billable/Non-Specific Code First , if applicable:Crohn's disease (K50.-)ulcerative colitis (K51.-) Type 1 Excludes congenital fistula (Q43.6) Codes K60.30Anal fistula, unspecifiedK60.31Anal fistula, simpleK60.311Anal fistula, simple, initialK60.312Anal fistula, simple, persistentK60.313Anal fistula, simple, recurrentK60.319Anal fistula, simple, unspecifiedK60.32Anal fistula, complexK60.321Anal fistula, complex, initialK60.322Anal fistula, complex, persistentK60.323Anal fistula, complex, recurrentK60.329Anal fistula, complex, unspecified