Q How is Anal
fistulas begin as anorectal abscesses. When the abscess opens spontaneously into
the anal canal (or has been opened surgically), a fistula
may occur. Approximately, 8-50% of perianal abscess
patients end up having an anal fistula.
causes of fistulas include tuberculosis, cancer, injury (trauma), Crohn's
disease, after Radiation therapy, anal Fissure, and
infections (actinomycoses, chlamydial etc). Fistulas may occur singly or in multiples.