DB50.1

ICD-11 MMS 2026-01

Anal fistula

Description

Anal fistula is an abnormal communication, hollow tract lined with granulation tissue connecting the primary opening inside the anal canal to a secondary opening in the perineal skin. They are usually associated with anorectal abscesses, and they are thought to be a chronic condition after an abscess evacuation.

Index terms

  • Anal fistula
  • Allingham ulcer
  • fistula in ano
Show allHide
  • perianal fistula

Exclusions from above levels

  • DB70.00 – Anal abscess
  • LB17 – congenital anomalies of the anal canal
  • 01 – Certain infectious or parasitic diseases
Show allHide
  • 02 – Neoplasms
  • 05 – Endocrine, nutritional or metabolic diseases
  • 06 – Mental, behavioural or neurodevelopmental disorders
  • 18 – Complications of pregnancy, childbirth and the puerperium
  • 22 – Injury, poisoning or certain other consequences of external causes

Sibling codes

  • DB50.0 – Anal fissure
  • DB50.2 – Anorectal fistula
  • DB50.Y – Other specified fissure or fistula of anal regions
  • DB50.Z – Fissure or fistula of anal regions, unspecified

Foundation entity

Anal fistula – http://id.who.int/icd/entity/206903882

Allowed postcoordination axes

Part of: DB50: Fissure or fistula of anal regions › 13: Diseases of the digestive system