ICD-10-CM > S00-T88 > T80-T88 > T81 > T81.8 > T81.83 T81.83 Persistent postprocedural fistula Non-Billable/Non-Specific Code Also , if applicable, disruption of internal operation (surgical) wound (T81.32-) Use Additional code, if known, for site of fistula such as:anal fistula (K60.3-)anorectal fistula (K60.5-)bladder fistula (N32.2)other female intestinal-genital tract fistulae (N82.4) Codes T81.83XA..., initial encounterT81.83XD..., subsequent encounterT81.83XS..., sequela