II. Epidemiology
- Uncommon (represents only 5% of Anorectal Abscesses)
III. Pathophysiology
- Infection begins at the perianal crypts along the Dentate Line and spreads via the intersphincteric groove
- Infection may also spread from an intraabdominal source (e.g. perforated colon)
- Perirectal Abscess spread to above levator ani Muscle
IV. Causes
V. Symptoms
- Rectal Pain (esp. with stooling)
- Urinary tract symptoms
- Urinary Retention
- Back Pain (referred pain from sacral nerve inflammation or compression)
VI. Signs
- Fever
- Tender, fluctuant mass may be present above the anorectal ring on Digital Rectal Exam
- External exam is typically unremarkable
VII. Differential Diagnosis
VIII. Imaging
- CT Pelvis
IX. Labs
X. Diagnosis: Rectal mucosa fullness on diagnostic testing
XI. Management
- See Perirectal Abscess
- Colorectal surgery or General Surgery Consultation
- Ischiorectal Abscess extending into the Supralevator Space
- Drain as with Ischiorectal Abscess via skin access
- Intersphincteric Abscess extending into the Supralevator Space
- Internal sphincterotomy through incision in the anal mucosa (as with Intersphincteric Abscess)
- Ischiorectal Abscess extending into the Supralevator Space
XII. References
- Marx (2002) Rosen's Emergency Medicine, p. 1952
- Roberts (1998) Procedures, Saunders, p. 649-51
- Sherman, Bahga and Vietvuong (2022) Crit Dec Emerg Med 36(7): 23-9