By examining either in OPD or under anesthesia
- One or multiple external openings
- Red tender painful swelling
- Area of induration
- Discharge – pus / blood
- Skin Excoriation
Not infrequently one can palpate internal opening as a nodule on the anal canal wall Irrespective of external openings, these is only one internal opening
Fistula with external opening in relation to the anterior half of anus and within 3.75 cm of anus lead to be direct type and those in relation to be posterior half of anus usually have curved tracks & may be horse shoe variety.
Sometimes reveal an internal opening or a hypertrophied papilla
- Probing : Fistula probing should be done very carefully as it can create false passage and one should avoid it, also infection can be introduced.
- X-ray chest – To rule out Pulm koch’s