Anal Fistula Specialist In Bozeman, Montana

What is an anal fistula?

An anal fistula is an abnormal tunnel between the anal canal or rectum and the skin surrounding the anus.

Most anal fistulas begin with an infection in one of the small glands inside the anal canal. When the gland becomes blocked, an abscess may form. The abscess can drain spontaneously or require surgical drainage, but the tunnel connecting the infected gland to the skin may remain long after the abscess is gone.

Patients may experience repeated cycles of swelling, pain, drainage, and temporary improvement. A small external opening may intermittently release blood, pus, or clear fluid.

Although anal fistulas often develop after an abscess, some patients do not remember having a significant abscess or infection.

What symptoms can an anal fistula cause?

Common symptoms include:

• Recurrent pain or swelling near the anus
• Persistent or intermittent drainage
• Repeated anal abscesses
• Skin irritation or itching
• A small opening or tender lump near the anus
• Bleeding
• Fever or worsening pain when an abscess develops

The drainage may stop temporarily when the external opening closes, only for pain and swelling to return as another abscess forms.

How are anal fistulas treated?

Anal fistulas rarely heal permanently without treatment. Surgery is usually required to eliminate the fistula and prevent recurrent infection.

The correct procedure depends on the location of the fistula and how much of the anal sphincter muscle it crosses. Dr. Zehnpfennig selects the treatment that offers the best chance of healing while preserving continence.

Fistulotomy

A fistulotomy is commonly used for shallow fistulas that involve little or no sphincter muscle. The fistula tract is opened and allowed to heal from the inside outward.

For appropriately selected fistulas, fistulotomy has a high success rate.

Seton placement

A seton is a soft surgical drain placed through the fistula tract. It allows ongoing drainage, controls infection, and prevents another abscess from forming.

Setons are often used before definitive repair of a complex fistula and may remain in place for several weeks or longer.

What does complex anal fistula surgery involve?

Complex fistulas may pass through a substantial portion of the anal sphincter, extend above the sphincter muscles, involve multiple branches, or occur in patients with inflammatory bowel disease.

Dividing too much sphincter muscle can impair bowel control. For this reason, complex fistulas often require a sphincter-preserving procedure.

Dr. Zehnpfennig performs advanced fistula repairs, including:

Endorectal advancement flap

An advancement flap closes the internal fistula opening using healthy tissue from inside the rectum or anal canal. This prevents continued contamination of the tract while preserving the sphincter muscles.

LIFT procedure

Ligation of the intersphincteric fistula tract, or LIFT, treats the fistula in the space between the internal and external sphincter muscles. The tract is identified, divided, and securely closed without cutting through the main sphincter complex.

TROPIS procedure

Transanal opening of the intersphincteric space, or TROPIS, is an advanced sphincter-preserving technique for selected complex fistulas. The infected intersphincteric portion of the tract is opened internally to allow drainage and healing while protecting the external sphincter.

Why should complex fistulas be treated by a colorectal specialist?

Complex fistulas require precise identification of the internal opening, secondary branches, abscess cavities, and relationship to the sphincter muscles.

Dr. Zehnpfennig has fellowship training in complex anal fistula surgery and develops an individualized treatment plan designed to achieve durable healing while minimizing the risk of recurrent infection and loss of bowel control.

If you have recurrent anal pain, swelling, drainage, or abscesses, call the office or request an appointment online.