Anorectal abscesses, primarily caused by E. coli infections from anal gland issues, are common in diabetics and immunocompromised individuals. They can be classified into perianal (60%), ischiorectal (30%), and others, with treatments including incision and drainage, antibiotics, and analgesics. Complications may include fistula formation and recurrences, with approximately 50% of patients potentially developing an anal fistula after drainage.

1. -Dr.Navya Teja

2. ANORECTAL ABSCESS
•MC organism – E.COLI
•Commonly occurs due to infection of anal glands
in relation to crypts-CRYPTOGLANDULAR
DISEASE (95%)
•Common in diabetics & immunocompromised
•Other causes-
o injury to anorectum
o Cutaneous infection ( boil)
o Blood born infections

3. PATHOPHYSIOLOGY
Originates from an infection arising in the
crypto glandular epithelium lining the anal
canal
The internal anal sphincter normally serves
as a barrier to infection passing from the gut
lumen to the deep perirectal tissues.
This barrier can be breached through the
crypts of Morgagni, which can penetrate
through the internal sphincter into the
intersphincteric space

4. PATHOPHYSIOLOGY
Once infection gains access to the
intersphincteric space, it has easy
access to the adjacent perirectal
spaces
Extension of the infection can
involve the intersphincteric
space 2–5%, ischiorectal space
20-25% , or even the
supralevator space 2.5%.

5. DIFFERENTIAL DIAGNOSIS FOR
ANORECTAL ABSCESS
•PERIURETHRAL ABSCESS
•BARTHOLIN ABSCESS
•TUBERCULOUS ABSCESS

7. WORKUP/INVESTIGATIONS
• MRI – IOC
• PERINEAL & ANAL USG- also useful
• CBC may show leukocytosis
• Pus cultures
• Blood cultures

8. CLASSIFICATION OF ANORECTAL ABSCESS
1. Perianal (60%)
2. Ischorectal (30%)
3. Submucous
4. Pelvirectal
5. Fissure abscess

9. Classification

10. PERIANAL
ABSCESS

12. PERIANAL ABSCESS (60%)
•Lies in region of subcutaneous
portion of EXTERNAL SPINCTER
•Usually results from suppuration of
anal gland or thrombosed ext pile or
any infected perianal condition

13. PERIANAL ABSCESS-CLINICAL FEATURES
•SEVERE PAIN in perianal region
with difficulty to sit
•O/E- tender,smooth,soft ,swelling
in the region

14. PERIANAL ABSCESS-TREATMENT
•I & D
•SITZBATH +ANTIBIOTICS+ANALGESICS
+L/A of ANAESTHETIC
AGENTS+LAXATIVES

15. ISCHIORECTAL
ABSCESS ( 30%)

16. ISCHIORECTAL FOSSA
•PYRAMIDAL IN SHAPE
•5CM DEPTH,2 CM WIDTH
•Right & left communicate with each other
through posterior spincteric space- HORSE
SHOE abscess

17. ISCHIORECTAL FOSSA- BOUNDARIES
•LATERALLY-fascia covering OBTURATOR
INTERNUS
•MEDIALLY- LEVATOR ANI & EXTERNAL
SPINCTER
•POSTERIORLY- SACROTUBEROUS
LIGAMENT & GLUTEUS MAXIMUS
•ANTERIORLY- UROGENITAL DIAPHRAGM
•BELOW- BY SKIN

18. ETIOLOGY
•Commonly it is due to extension of
lower intermuscular anal abscess
laterally through ext spincter
•Fat in fossa is more prone to infection
coz its LEAST VASCULARISED

19. CLINICAL FEATURES
•Tender,indurated,brawny
swelling in the skin over
ischiorectal fossa with high fever
•Swelling – not localised
•Fluctuation - absent

20. TREATMENT
•In LITHOTOMY position,
CRUCIATE shaped incision,
Followed by DE ROOFING &
DRAINAGE of pus
•Presence of any internal opening
to rectum should be looked for

22. COMPLICATIONS
Fistula-in-Ano
Fournier’s Gangrene
Death
Fecal Incontinence

23. PROGNOSIS
Drainage alone results in cure for
50%.
50% will have recurrences and
develop an anal fistula.