Fistulotomy - Anal Fistula Surgery

What is an anal fistula?

An anal fistula is an abnormal tract that connects the inside of the anus or rectum to the outside perianal skin. It arises over time from an inflammatory process, such as an infected anal gland or an abscess near the anus, which lead to the development of a fistula extending to nearby tissues. While infections are a common cause, non-infectious conditions like Crohn’s disease, physical trauma, or prior surgeries can also contribute to their development. These fistulas vary in complexity, with some being relatively straightforward to treat and others requiring advanced surgical intervention due to their involvement of deeper tissues.

If you suspect an anal fistula, consulting a colorectal surgeon is essential for accurate diagnosis and effective treatment.

Why anal fistula surgery?

Anal fistulas rarely heal without treatment, and surgery is often necessary to resolve the condition effectively. Without proper surgical drainage and repair, these abnormal tracts allow infections to persist, causing significant pain, swelling, and continuous discharge. In cases of complex or more advanced fistulas, the sphincter muscles may also be involved, complicating bowel control and leading to issues like fecal incontinence, which may require fecal incontinence surgery.

Left untreated, a fistula can perpetuate chronic infections or lead to systemic complications like sepsis (a life-threatening infection) and, in some cases, increase the risk of anal cancer. 

A fistulotomy is a surgical procedure designed to treat anal fistulas by accessing the tract to allow it to heal while minimizing damage to the surrounding sphincter muscles. The approach may include incision and drainage or seton placement (a surgical thread used to keep the tract open and promote gradual healing), depending on the complexity of the fistula.

All forms of surgical treatment, whether they be big or small, carry risks. For anal fistula surgery, or a fistulotomy, these typically include:

The fistulotomy procedure - What to expect

The primary purpose of a fistulotomy is to remove all the pus and fluids inside the fistula and affected area. Removing infected material will help the fistula opening heal faster and close the abnormal tunnel.

A fistulotomy is a minor outpatient surgery, meaning you can go home the same day. Before the procedure, a nurse or doctor will clean the affected area, confirm the surgical plan, and answer any questions you may have. An anoscope – a tool used to help doctors see inside the anus – may be used to help plan the surgery. Local anesthesia is typically used to numb the area and ensure you feel no discomfort, while general anesthesia may be recommended for more complex cases. The procedure itself can last anywhere between a few minutes to an hour depending on the size of the fissure at the time of surgery. Typically, your doctor will inform you of the expected duration beforehand.

During the procedure, one of our surgeons will use a scalpel to cut into the fistula. Slight pressure will be applied to the site and the anal abscess will be drained. Subsequently, infected tissue surrounding the area will be entirely removed. Your surgeon will then stitch the incision and leave it to heal. In circumstances where the fistula is too large to stitch, the wound will be packed with gauze and be left to heal in the open.

You may need to take antibiotics before surgery. Routine blood work is usually not needed but may be ordered prior to surgery based on the patient's age and the presence of any existing medical problems. Your surgeon may recommend imaging tests like an ultrasound or MRI if the fistula is complex or its location is unclear, and further tests may be necessary to determine if the condition is related to Crohn’s disease.

After the procedure

Recovery time for a fistulotomy will vary, but you should feel back to normal within a few weeks. Residual pain may last up to a week after surgery. Be sure to keep the area clean and dry to avoid the possibility of infection. Itchiness or soreness is common, however let your doctor know if you experience swelling or excessive pain.

You will need to arrange for a ride home the day of your surgery and we recommend someone stay with you for the first 24 hours at home. When you leave the facility after surgery, we will want you to go home and rest. Avoid making any other plans on the day of your surgery. Starting the following day, you can increase your activity as you feel up to it.

You will likely be given a prescription for pain medication following your surgery. The recovery nurse will discuss a pain control plan following surgery specific to you and your needs including activities like ice applied over incisions and a medication regimen. Oftentimes we will recommend taking Tylenol and Advil (same as Motrin, Ibuprofen) or Aleve in addition to the narcotic pain medication. You can refer to our surgery guidelines for more detailed, pre-op and post-op instructions.