What Is Sphincterotomy?

What to Expect When Undergoing This Procedure

Sphincterotomy, also called a lateral internal sphincterotomy, is a type of procedure that is used to stretch or to cut the anal sphincter. The anal sphincter is the group of muscles connected to the rectum, at the end of the digestive tract, through which bowel movements are passed. This surgery is done when an anal fissure (a break in the skin of the anus) hasn’t gotten better after trying other treatments. Fissures can bleed and be painful and in some cases, may take time to heal. 

In most cases, fissures can be healed at home, sometimes even without treatment. However, when healing is taking too long, surgery may be considered. Sphincterotomy is considered the gold standard for treating chronic anal fissures, and the success rate is usually reported as being about or greater than 95 percent, depending on the study.

Having a fissure come back again (recur) after a sphincterotomy is rare and most patients are satisfied with the results of the procedure.

What Are Anal Fissures?

Trauma to the tissue lining of the anal canal can lead to a tear or a break, which is called a fissure. Anal fissures can cause symptoms of pain, bleeding, itching, and pain during bowel movements. Fissures that are superficial and may heal fairly quickly without any treatment are considered to be acute. Those that are deeper and are still not healed after treatment or after several weeks may be considered chronic.

Fissures are most often caused by passing a hard stool (which could be but is not always associated with being constipated).

Having certain medical conditions, such as hypothyroidism, obesity, and chronic constipation are also associated with an increased risk of developing an anal fissure. 

Initially, anal fissures are usually treated more conservatively, with home remedies. In order to make stools softer and easier to pass, eating more fiber and using stools softeners may be recommended. If stools can be passed without straining, it may help the fissure to heal and also reduce pain during bowel movements.

Drinking more water may also help in making sure stools are not too hard, and sitz baths (sitting in a small amount of warm water) may help the anal area to feel better and also promote healing. In some cases, a local anesthetic ointment may be prescribed in order to reduce pain during bowel movements.

Another treatment that might be used is botox injections, which are usually used when other conservative measures haven’t worked. Botox blocks the nerves that cause the anal sphincter to spasm, which aids in helping the tear in the tissue to heal. 

Purpose of a Sphincterotomy

When at-home treatments and/or botox injections are not working to heal a chronic anal fissure, a sphincterotomy may be considered. The anal sphincter has two muscles: an internal and an external muscle. The external muscle is under voluntary control (it can be clenched and unclenched consciously) and the inner muscle is controlled by the nervous system (it cannot be consciously controlled).

The muscles work together to hold stool in the rectum (continence) and conversely, to let a bowel movement pass out of the body. 

Risks and Contraindications

In the majority of cases, a sphincterotomy is successful and patients are satisfied. However, as with any type of surgery, there are certain risks and there is the potential for complications. Some of the complications that can occur with sphincterotomy include:

  • Temporary incontinence: Some patients have incontinence in the period immediately following surgery. This can include the leakage of stool or difficulty in controlling gas. However, in most cases, this only occurs in the first week or two after the surgery. It is rare to experience fecal incontinence after the healing period.
  • Hemorrhage. Hemorrhaging, or bleeding can happen after a surgical procedure. In the case that there is unexpected bleeding, some sutures (stitches) may need to be used to stop the bleeding.
  • Perianal abscess. It is rare, but in some cases where the closed technique is used, an abscess (a collection of pus) can develop, along with an anal fistula. If this does happen, the abscess may need to be drained and another procedure to remove the fistula, called a fistulotomy, may need to be done.

Before the Procedure

A sphincterotomy is a type of minor surgery so the surgeon will give instructions as to what should be done to prepare. For general anesthetic, it may be necessary to stop eating or drinking at midnight the night before the procedure. For local anesthetic, the instructions may be the same or in some cases, eating and drinking might be allowed up to a certain point prior to the surgery.

Blood thinners or other medications that have the effect of thinning the blood might need to be stopped for several days before surgery.

It’s important to tell the physician’s office about all medications and supplements currently being taken. 

Patients will not be able to drive themselves home from this procedure, so a friend or family member will be needed to drive. 

At check-in, there will be a medical history taken that will include questions about any current medications or supplements, any allergies, and any past reactions to anesthesia or other medications. Release forms will need to be signed before the preparation for the procedure can begin. An IV will be placed for fluids and any medications (such as anesthesia or sedatives) that are needed. When it is time to begin the procedure, the patient is wheeled into the operating room.

During the Procedure

The internal anal sphincter is always under a certain amount of tension. When this tension becomes too great it can lead the muscle to experience a spasm. Spasms could contribute to the development of a fissure or prevent one from healing. During a sphincterotomy, an incision is made in the inner anal sphincter muscle, which reduces some of this tension. Blood flow to the area is also increased after the procedure, which helps the fissure to heal. 

A lateral internal sphincterotomy may be performed as “open” or “closed.” The type of procedure that is done will depend on a number of factors. In the open surgery, an anoscope is inserted into the anal sphincter to see the muscles and the fissure, and the incision is made. In the closed procedure, a small incision is made between the inner and the outer anal sphincter muscle, the scalpel is inserted inside, and an incision is made in the internal muscle. The closed technique may be preferred by those surgeons that are specially trained to perform the surgery in this way.

In most cases, a sphincterotomy is done as an outpatient procedure. It may be done under local or general anesthetic. In some cases, the incision may be left open to heal; in others, it may be closed up. Most people will be able to go home the same day as the procedure. 

After the Procedure

After the surgery, a dressing might be placed inside the anus. When the surgery is complete, patients are monitored for a few hours to ensure that everything has gone well. After that period in recovery is over, patients will either be discharged to go home or if a hospital stay is needed, will be taken to a hospital room. 

Recovery at Home

Most people will need at least a day to recover from general anesthesia and find they need to stay home from work and regular activities for about a week (or in some cases, about two weeks). Patients may be sent home with a prescription for pain relievers or other medications and the instructions on how to take them. In some cases, patients report that the pain experienced after the procedure is less than that which was caused by the anal fissure.

Other home care instructions may include how to use a sitz bath several times a day, how to eat a high fiber diet to help stools become softer and easier to pass, and to drink plenty of water or other fluids. In some cases, stool softeners may also be prescribed.

In the first few days, the most pain may occur during a bowel movement, so it will be important to keep stools soft and to avoid straining.

There may be some bleeding for a week or more after the surgery, but it should be seen mostly on the paper after wiping.

Follow-Up

Recovery is usually uneventful, but any excessive pain or bleeding should be reported to a healthcare provider immediately. Most people feel better and have less pain in a few days; however, it may take about 6 weeks for the incision to heal completely.

Having incontinence that persists after the first few days is not common, but if it continues, it should be discussed with a healthcare provider. If the fissure returns (a rare occurrence) it may need further treatment.

A Word From Verywell

Fissures are common and they usually heal on their own. When they don’t, a sphincterotomy is a good alternative that usually results in a full recovery. Most people find that the pain from the surgery is less than the fissure pain and they can go back to work or school fairly quickly.

Taking care to follow instructions about diet, activity level, and fluid intake, as well as any other directions the surgeon gives will help the process of healing. Concerns about incontinence, pain, or any other side effects can be brought up with the surgeon both before and after the procedure to help lessen anxiety about having sphincterotomy surgery.

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Article Sources

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  1. Wollina U. Pharmacological sphincterotomy for chronic anal fissures by botulinum toxin a. J Cutan Aesthet Surg. 2008;1(2):58-63. doi: 10.4103/0974-2077.44160

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