Perianal abscess and fistulas, pilonidal cyst – surgical treatment

1. Big picture

This topic is about septic and chronic inflammatory disease around the anus and natal cleft. The examiner wants you to know one central surgical rule:

Abscess = drain urgently. Fistula = define anatomy and treat without destroying continence. Pilonidal abscess = drain; chronic pilonidal sinus = elective definitive surgery if symptomatic or recurrent.

The clinical workflow is:

Painful perianal swelling / discharge / fever
        ↓
Inspect + digital rectal examination if tolerated
        ↓
Is there abscess/sepsis?
        ↓
Yes → urgent incision and drainage
        ↓
Later: assess for fistula, Crohn’s disease, recurrence, complex anatomy
        ↓
Defin