What Is a Fistula Seton?

A seton might be placed to help heal a fistula

A fistula seton is a special type of flexible material that’s surgically placed into a fistula. A fistula is an abnormal connection, much like a tunnel, that runs between two internal organs or between an organ and the skin. An example is a rectovaginal fistula that can form between the rectum and the vagina.

The seton allows the fistula to drain any fluid that develops and may aid in healing. This article will discuss why a seton will be placed in a fistula, preparation for the procedure, and what can be expected during recovery.

Female adult doctor talking with a male patient in protective medical masks in an exam room.

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A fistula is an abnormal tunnel that forms between two body structures. It can be associated with various diseases or conditions, including as a complication of Crohn’s disease, a type of inflammatory bowel disease causing inflammation of the digestive tract. Special steps must be taken to heal a fistula and avoid further complications, as well as pain or discomfort.

A seton may be placed in the fistula so that it does not close up by itself at one opening. If that happens, it could cause the formation of an abscess. An abscess is a collection of pus that can lead to further complications. 

The seton is a flexible type of tubing or string-like material that may be made of silicone, nylon, silk, or a surgical suture. It is threaded through the fistula. This keeps the fistula open so that it may drain and heal more cleanly.

Conditions Associated With Fistula

A fistula can occur because of a disease or condition. Some of the problems that can cause a fistula include:

Fistula Seton Placement Process

The placement of a fistula seton is a surgical procedure. It is performed on an outpatient basis. Patients are put under anesthesia for the placement of a seton.

There may be a preparation procedure before surgery. For instance, if you have an anal fistula that is between the anus and the skin, you may be asked to use an enema. The surgeon will give you any special instructions on how to prepare.

The two openings of the fistula will be identified and the seton will be threaded through it. The seton may be knotted or otherwise connected so that it forms a continuous loop.

Who Does It?

For fistulas in the perianal area or that involve digestive organs such as the anus, rectum, or colon, a gastroenterologist (a specialist of disorders of the stomach and intestines) or a colon and rectal surgeon may place a seton. In certain instances, a general surgeon may place the seton.


In general, the two types of setons that might be placed to treat a fistula are: 

  • A loose seton is one that is placed and left for several weeks to allow the fistula to drain. Scar tissue forms around the seton, in the fistula tract.
  • A cutting seton is placed and then gradually tightened. The tightening is done over a series of weeks. Eventually, the seton makes its way through the fistula tract, opening it up. This is done less commonly than a loose seton.

How to Prepare

The preparation will depend on the type of fistula. You may be asked to fast, having nothing to eat or drink for several hours before the operation or starting the night before.

For a seton that’s placed in the rectal area, your doctor may recommend that you use an enema. The enema involves injecting liquid into the rectum to help empty the rectum of any stool, making for easier placement of the seton. 

General anesthesia may be used, which will require you to have an intravenous (IV) line placed. There may be other medications given to prevent infection.

The procedure is done on an outpatient basis. If you are getting anesthesia, you will need to be driven to and from the procedure and are not allowed to drive yourself. Having a friend or family member to help at home after the procedure is also a good idea and will help with recovery.


You may be prescribed a stool softener after the procedure. If the seton is placed in or around the anal area, having stools that are soft and easily passed will help prevent pain and discomfort during bowel movements.

Keeping the area clean will also be part of the aftercare process. This could include taking sitz baths (sitting in warm, shallow water) or changing dressings as needed. Applying ice to the area may also be recommended for a short period of time to lessen any swelling and inflammation.

You may also be given prescription pain medication for use in the days after the procedure. This should be taken as directed. Over-the-counter (OTC) pain remedies, including nonsteroidal anti-inflammatories (NSAIDs, such as ibuprofens like Advil or Motrin or naproxen sodium like Aleve) or Tylenol (acetaminophen), may also be recommended. 

There will be follow-up visits to check the seton placement. If it is a cutting seton, there will be regular appointments to tighten the seton and check on its progress.


A seton is a flexible tube or thread that is placed through a fistula. The seton is a step in healing the fistula and in preventing further complications. A seton may be left in place for several weeks to several months. Regular checkups will be needed to keep an eye on the fistula and the seton.

A Word From Verywell

Learning that a seton will be placed and left for several weeks or even months can be stressful. In some cases, the length of time a seton may be needed might not be known when it is placed. In addition, there could be a need for more than one seton if there are multiple fistulas.

For that reason, it’s important to ask questions and get as much information as possible about the procedure and the recovery. Understanding what will happen at every step will be the best way to lower your stress levels and do everything needed to ensure the best chance of a full recovery.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute of Diabetes and Digestive and Kidney Diseases. Colonic & anorectal fistulas. Updated August 2019. 

  2. Slinger G, Trautvetter L. Addressing the fistula treatment gap and rising to the 2030 challengeInt J Gynaecol Obstet. 2020;148 Suppl 1(Suppl 1):9-15. doi:10.1002/ijgo.13033

  3. Bolshinsky V, Church J. How to insert a draining seton correctlyDis Colon Rectum. 2018;61(9):1121-1123. doi:10.1097/DCR.0000000000001132

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.