Description

Localized infection and accumulation of purulent material adjacent to anus or rectum

Etiology

• Anal crypt gland infection, with spread to adjacent areas separated by muscle and fascia:
  • Perianal:
    • Most common
    • Usually with red bulge near anus
  • Ischiorectal:
    • Large potential space
    • May become very large before diagnosed
    • Can communicate posteriorly with other side forming “horseshoe” abscess
  • Intersphincteric:
    • Contained at primary site of origin between internal and external sphincters
  • Supralevator:
    • Very deep above levator ani
    • Needs operative débridement under general anesthesia
    • Often systemic symptoms before diagnosis is made
• Bacterial cause is typically a mix of stool species