Anal fistula

How do anal fistulas occur?

When a perianal gland becomes infected, an abscess can form in the area. This abscess can cause a fistula.

The infection causes pain, fever and often painful swelling around the anus.

Anal fistulas and abscesses can occur in anyone. People suffering from Crohn's disease are more likely to develop fistulas.

Diagnosis

Diagnosis is often made after an examination of the anus. Sometimes it is helpful to use a short lighted viewing tube (anoscope) to examine the fistula internally.

Treatment

Only surgery offers a definitive solution for anal fistulae. Usually, the opening of the fistula is close to the anus, below the sphincter muscle. This makes it easy to treat the fistula by cutting open the tunnel. The wound is left open after surgery and heals by itself.

Sometimes the fistula runs through or around the sphincter. In this case, the fistula cannot be cut without damaging the sphincter. The treatment is then a little more complicated. First, a "seton" or "tress" (rubber band or string) is placed through the fistula that prevents new abscesses from forming. This rubber band stays in place for several weeks.

Depending on the location of the fistula, there are several options for definitive treatment:

• Low fistula: this fistula affects only a small part of the sphincter. Often the fistula can be passed through without danger of incontinence.
• Higher fistula: here the fistula runs too deep through the sphincter. In this case, surgery must be performed to spare the sphincter. Your doctor will discuss with you which treatments are possible.