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Beverly Hills · 435 N. Bedford Dr., Suite 308Mon–Fri 9:00 am – 5:00 pmMost PPO insurance accepted
Allen KamravaMD · MBA · FACS · FASCRS

Procedure

Operative

Seton Placement

A soft, flexible loop placed through the fistula tunnel to keep it draining — it calms the infection down, protects the muscle, and stays with you for weeks to months while the next step is planned.

Request a consultationSurgery is arranged with a coordinator by phone.
Setting
Operative
Anesthesia
Typically placed in the operating room under anesthesia, often during the exam that maps the fistula
Back to work
With a draining seton, most patients are back to normal activity within a day or two
Pain relief
A foreign-body awareness at first is normal; most discomfort settles within a few days, helped by warm sitz baths
Success rate
80-100% (Cutting Seton)
Recurrence
0-16%

What it is

What is a Seton?

A seton is a thin, flexible drain, often made of silk, rubber, or a vessel loop, that is passed through an anal fistula tract to facilitate drainage, promote fibrosis, and in some cases, gradually cut through the sphincter muscle. Seton placement is the preferred initial treatment for complex anal fistulas, particularly those involving a significant portion of the anal sphincter muscles, as it controls sepsis while preserving continence. There are two primary types of setons: draining (loose) and cutting.

Draining (Loose) Seton

A draining, or loose, seton is placed through the fistula tract and tied loosely to itself. Its purpose is to keep the tract open, allowing pus and inflammatory fluid to drain continuously. This prevents the formation of recurrent abscesses and allows the acute inflammation to resolve. A draining seton does not cure the fistula but serves as a crucial temporizing measure, maturing the fistula tract and creating a stable, uninfected pathway that makes subsequent definitive repair (like an advancement flap or LIFT procedure) safer and more effective.

Cutting Seton

A cutting seton is tied tightly around the encircled sphincter muscle. Over time, the seton is progressively tightened in an office setting. This gradual pressure causes the seton to slowly cut through the sphincter muscle, while simultaneously inducing fibrosis and scarring behind it. This process allows the muscle to heal as it is divided, theoretically preserving sphincter function and preventing the formation of a large gap that would lead to incontinence. While effective, this method is associated with more pain and a higher risk of continence impairment compared to sphincter-preserving repairs.

Am I a candidate?

Who is a Good Candidate for Seton Placement?

Seton placement is ideal for patients with complex anal fistulas where a primary fistulotomy would risk incontinence. This includes:

  • High Transsphincteric Fistulas: Fistulas that cross a significant portion (>30-50%) of the external anal sphincter.
  • Anterior Fistulas in Females: These often involve a more delicate sphincter complex.
  • Patients with Pre-existing Incontinence: Any division of the sphincter is avoided to prevent worsening symptoms.
  • Crohn's Disease: Draining setons are a cornerstone of managing fistulizing perianal Crohn's disease, often used long-term for drainage.
  • Recurrent Fistulas: After previous failed repairs, a seton provides drainage and allows inflammation to subside before another definitive repair is attempted.

A cutting seton may be considered in patients with high complex fistulas who are not candidates for or have failed other sphincter-preserving procedures, and who accept the potential risks to continence.

How it's done

  1. 1Under anesthesia, the surgeon passes a thin, soft loop — often a silicone vessel loop — through the full length of the fistula tunnel.
  2. 2The loop is tied loosely to itself, so it sits in the tract like a wick and holds the tunnel open.
  3. 3Continuous drainage is the whole point: it stops pus from building back up into an abscess while the inflammation settles.
  4. 4You go home the same day. The seton stays in place for weeks to months, until the tract is quiet enough for a definitive repair.

What to expect

  1. Same day

    Home once the anesthesia wears off. You can feel the loop — that's normal, and it fades into the background for most people.

  2. First few days

    Mild soreness and some drainage. Most patients are back to normal activity within a day or two.

  3. Weeks to months

    You live with the seton. Ongoing drainage is expected — it means it's working. Sitz baths and a small pad keep things comfortable; the tract quietly matures underneath.

  4. The next step

    Once inflammation has settled, the seton usually comes out at the time of a definitive repair, such as a LIFT or advancement flap. In some situations — fistulizing Crohn's disease especially — a draining seton stays in long-term on purpose.

  5. If a cutting seton is used

    A different plan: the loop is tightened in stages at office visits and slowly works through the muscle over weeks to months, letting scar form behind it. Your surgeon will discuss this specifically if it applies.

Risks & considerations

What are the Risks?

Seton placement is generally a very safe procedure. The risks depend on the type of seton used.

  • Discomfort: A loose draining seton may cause a foreign body sensation or minor irritation. A cutting seton is associated with significant pain, especially after tightening sessions.
  • Drainage: Persistent drainage from the seton is expected and is the intended function.
  • Incontinence: Draining setons have a very low risk of impacting continence. Cutting setons, however, carry a definite risk of causing or worsening incontinence to flatus or stool, although the risk is lower than a primary fistulotomy for a high fistula.
  • Recurrence: The fistula may recur after the seton is removed if a definitive repair is not performed or is unsuccessful.
  • Seton Migration or Breakage: Rarely, a seton may fall out prematurely or break.

Sources

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