Fistula in ano short presentation for undergraduates

1. Fistula In Ano
Kishore SR
Oman Medical College

2. Contents
• Anatomy
• Etiology
• Clinical features
• Assessment and Investigations
• Management

3. Anatomy of the Anal Canal

5. Etiology
• Obstruction of the Anal Gland
▫ In the vast majority of cases, fistula-in-ano is caused by a previous
anorectal abscess. (cryptoglandular infection)
• Iatrogenic
• Crohn’s disease
• Anorectal trauma
• Anorectal Carcinoma
• Others (radiation therapy, actinomycoses, tuberculosis, and
lymphogranuloma venereum secondary to chlamydial infection)

6. Clinical Features
• Patients often provide a reliable history of previous pain, swelling,
and spontaneous or planned surgical drainage of an anorectal
abscess. Signs and symptoms of fistula-in-ano, in order of
prevalence, include:
• Perianal discharge
• Pain
• Swelling
• Bleeding
• Diarrhea
• Skin excoriation
• External opening

7. Assessment and Investigations
• Physical examination under Anesthesia
is the mainstay of diagnosis.
• Digital rectal examination (DRE) may
reveal a fibrous tract or cord beneath
the skin
• Anoscopy is usually required to identify
the internal opening.
• Proctoscopy is also indicated in the
presence of rectal disease (e.g., Crohn
disease or other associated
conditions).
• MRI for high complex fistulas

8. • Goodsall’s Rule

9. Management
• Low lying fistulas can be simply laid
open and allowed to heal.
• In complex ones involving the
sphincter, it can be probed using a
lacrimal probe and seton is passed
and allowed to drain.
• A tighter seton will gradually cut
through the sphincters and allow to
heal behind the seton.

10. • High fistulas can be treated with an anorectal
advancement flap.

11. Thank you