PANCE Blueprint GI and Nutrition (9%)

Rectal Abscess and Fistula (Lecture)

Patient will present as → a 47-year-old man with severe rectal pain when he defecates. He has a fever of 102.2 F (39 C). On exam there is perianal swelling, redness and tenderness. A palpable mass is felt at the anal verge as seen here.

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What disease should be considered with fistula in ano?
Crohn’s disease
What is a sitz bath?
Sitting in a warm bath (usually done after bowel movement and TID)

Anorectal abscess is a result of infection, whereas fistula is a chronic complication of an abscess.

  • Abscesses produce painful swelling at the anus as well as painful defecation. Examination reveals localized tenderness, erythema, swelling, and fluctuance; fever is uncommon.
  • Deeper abscesses may produce buttock or coccyx pain and rectal fullness; fever is more likely.

On examination, an abscess will be red and tender and may be discharging purulent or hemorrhagic fluid. There will likely be some degree of surrounding cellulitis.

Anorectal fistula is an open tract between two epithelium-lined areas and is associated with deeper anorectal abscesses

  • Communication between rectum and perianal skin
  • Generally located within 3 cm of the anal margin
  • Fistulae will produce anal discharge and pain when the tract becomes occluded.

Anal Abscess

  • Clinical - perirectal tender swollen mass
  • CT scan of pelvis only if recurrent

Fistula in Ano (Perianal Fistula)

  • Anoscopy

Treatment of abscess requires surgical drainage, followed by warm-water cleansing, analgesics, stool softeners and a high-fiber diet are prescribed for all patients

  • Prompt incision and adequate drainage are required and should not wait until the abscess points. Many abscesses can be drained as an in-office procedure; deeper abscesses may require drainage in the operating room.
  • Antibiotics are needed for high-risk patients

Fistula must be treated surgically.

Fistula Causes


A fistula is a connection or passageway formed abnormally between two epithelium-lined vessels or organs. Causes of enterocutaneous fistulas can be summarized by the mnemonic “FRIEND.” The “FRIENDs” of a fistula include Foreign body, Radiation, Infection, Epithelialization, Neoplasm, and Distal obstruction.

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Brian Wallace PA-C Podcast: The Rectum, Hemorrhoids and Hernias (Prev Lesson)
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