Anorectal Abscess

Symptoms: severe perianal pain (constant, throbbing), worse sitting / defaecating; swelling; fever; difficulty passing urine. Examination: perianal tenderness, induration, fluctuance. Must distinguish more proximal abscesses: • Perianal — most common; superficial. • Ischiorectal — deeper, lateral, larger. • Intersphincteric — between internal + external sphincters; may not be visible externally; deep tenderness on PR. • Supralevator — above pelvic floor; presents with deep pelvic pain, fever, urinary; need MRI / CT. Imaging: MRI for deep / recurrent / Crohn's-related to define fistula tract.