A seton is a therapeutic device, typically a thin piece of silicone or surgical suture, placed temporarily within a complex anal fistula tract. Its primary function is to keep the abnormal tunnel open, allowing pus and infected fluid to drain continuously. This constant drainage prevents the formation of a painful abscess, a common complication if the fistula closes prematurely. The seton helps reduce inflammation and allows the tract walls to mature, preparing the area for a potential second-stage procedure to close the tunnel.
Determining the Right Time for Removal
The decision to remove a seton drain is made by the surgeon based on clinical signs that the fistula tract has achieved sufficient healing. The primary criteria is confirmation that acute infection and inflammation have subsided, marked by a substantial reduction or complete cessation of purulent drainage. Regular check-ups allow the surgeon to assess the condition of the tract and the surrounding tissue.
A draining seton remains in place for several weeks to many months to create a healthy, fibrotic tract without cutting through the sphincter muscle. Its removal signals that the area is clear of infection and ready for a definitive repair procedure, such as an advancement flap or the Ligation of the Intersphincteric Fistula Tract (LIFT) procedure. This differs from a “cutting seton,” which is gradually tightened until it slowly cuts through the muscle and falls out on its own.
The seton is typically removed when the fistula tract has narrowed significantly and the surrounding tissue has healed enough to support the next step in treatment. The goal is to create a stable pathway that can be addressed surgically to finally close the opening while preserving the function of the anal sphincter muscles. The timing for removal is individualized, depending on the patient’s underlying condition and the complexity of the fistula.
The Step-by-Step Removal Process
The removal of a draining seton is most often a quick procedure performed in the surgeon’s outpatient clinic rather than an operating room. To ensure comfort, the surgeon may inject a local anesthetic into the skin and tissue around the external opening of the fistula tract. The patient is typically positioned on their side with knees drawn toward the chest, or sometimes in the prone jackknife position, to provide clear access to the anal area.
Once the area is numb, the surgeon locates the knot or closure point of the seton, which is usually situated just outside the anal opening. The seton material, which is secured in a loop, is severed with surgical scissors or a scalpel at this external point. The surgeon then grasps one end of the cut seton and gently pulls the entire length of the tubing or thread out through the fistula tract.
Patients generally report feeling a sensation of pressure or a slight tugging as the seton is extracted, but the process is usually over in less than a minute. The local anesthetic makes the procedure manageable, and the quick nature of the removal minimizes discomfort. Since the seton has maintained an open channel, the extraction is generally smooth and does not involve any new incisions.
Post-Removal Care and Recovery
Following the removal of the seton, the patient can expect some immediate, minor drainage from the small remaining wound where the drain exited. This discharge may include a small amount of blood or serous fluid for the first few days as the final portion of the tract begins to close. The surgeon will likely advise wearing a small gauze pad or liner to manage this minimal discharge and keep the area dry.
Wound care at home centers on maintaining hygiene and promoting healing, often through the use of sitz baths. Sitting in a few inches of warm water for 10 to 15 minutes, several times a day, particularly after bowel movements, helps to clean the area and soothe residual discomfort. Gently pat the area dry afterward, avoiding harsh rubbing or the use of perfumed soaps or harsh chemicals.
Pain following a seton removal is typically mild and temporary, managed effectively with over-the-counter pain relievers such as acetaminophen or ibuprofen. Most individuals return to non-strenuous daily activities within a day or two. However, avoid activities that place direct, prolonged pressure on the area, such as extensive cycling or heavy weight lifting, for about two weeks.
Preventing constipation remains a priority. Maintaining a high-fiber diet and using stool softeners, as recommended by the doctor, is important to ensure soft, easy-to-pass bowel movements.
Patients must be vigilant for warning signs that could indicate a complication or a recurrence of infection. Immediate contact with the healthcare provider is required if symptoms include a fever above 101°F, new or significantly increased pain not relieved by medication, or the return of thick, foul-smelling, or excessive drainage. These signs suggest the formation of a new abscess or that the fistula tract has not closed as expected.