A fistula-in-ano is an abnormal connection between the anal canal and the perianal skin. It is usually caused by a previous perianal abscess and can be classified based on its anatomical location. Common symptoms include discharge, pruritis ani, and pain. Diagnosis involves an examination, sometimes along with imaging tests like endoanal ultrasound or MRI to determine the internal opening, external opening, course of the fistula, and any complex extensions or underlying conditions. Treatment depends on the type of fistula but may include procedures like fistulotomy, seton placement, or flap repairs. Follow up care focuses on hygiene, pain management, and prevention of recurrence.

1. FISTULA-IN-ANO
Dr.Amna Altaf
PGR SIII
SHL/SIMS

2. What is fistula in ano?
 A fistula in ano or anal fistula is chronic
abnormal communication usually lined to
some degree by granulation tissue which runs
outward from the anorectal lumen to an
external opening on the skin of the perineum
or buttok.

3. Fistula in ano

4. Risk factors:
Nearly always associated with previous perianal abscess
Crohn’s disease
Diabetes mellitus
Tuberculosis
Actinomycosis
Lymphogranuloma venereum
Rectal duplication
Foreign body
Trauma
Radiotherapy
Immunocomproised
Malignancy

6. Classification
 Parks classification
1.Intersphincteric
2.Trans-sphincteric
3.Suprasphincteric
4.Extrasphincteric

7. Fistula in ano

8. Fistula in ano
1.Low anal fistula
2.High anal fistula

9. Fistula in ano
1.Simple
2.Complex

10. Presentation
Intermittent discharge
Pruritis ani
Pain
Previous episodes of anal sepsis

11. History
 Full medical history
including obstetrical
gastrointestinal
anal surgical
continence

12. examination
DRE:
area of induration, fibrous tract and
Internal opening may be felt.
Proctosigmoidoscopic inspection:
nessecsory to see rectal mucosa for any
underlying disese.

13. Key points for EUA
1.Site of internal opening
2.Site of external opening
3.Course of primary tract
4.Presence of secondary extention
5.Sphincter strength
6.Presence of other conditions complicating the
fistula

14. Goodsall’s rule

15. Imaging studies
1.Fistulography
2.Endoanal USG
3.MRI

16. Fistulography

17. Fistulogram

18. Endoanal USG

19. Endoanal USG

20. MRI

21. MRI

22. TREATMENT OPTIONS
Fistulotomy
Fistulectomy
Setons
Fibrin Glue
Anal fistula plug
Advancement flap

23. FOLLOW UP CARE
Perianal baths
Analgesics for pain
Stool bulking agents
Good perianal hygeine