by EBSCO Medical Review Board
(Sphincterectomy, Anal; Surgery for Anal Fissures; Lateral Internal Sphincterotomy; LIS)


Anal sphincterotomy is surgery to treat chronic anal fissures. An anal fissure is a painful tear in the lining of the anus.

Anal Fissure
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Reasons for Procedure

This surgery is done to ease muscle spasms that prevent fissures from healing.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • Excess bleeding
  • Problems from anesthesia, such as wheezing or sore throat
  • Infection
  • Blood clots
  • Inability to control the leakage of gas or stool from the rectum
  • Anal abscess or fistula formation

Things that may raise the risk of problems are:

What to Expect

Prior to Procedure

The surgical team may meet with you to talk about:

  • Anesthesia options
  • Any allergies you may have
  • Current medicines, herbs, and supplements that you take and whether you need to stop taking them before surgery
  • Fasting before surgery, such as avoiding food or drink after midnight the night before
  • Whether you need to use an enema before surgery
  • Whether you need a ride to and from surgery


The doctor may give:

Description of Procedure

Any skin tags near the anal fissure will be removed. A cut will be made on the anal sphincter muscle. This will relax the sphincter and allow it to stretch, taking pressure off the fissure. A bandage will be placed over the area.

How Long Will It Take?

Less than 1 hour

Will It Hurt?

Pain and swelling are common in the first few days. There may be some pain after bowel movements. It is often not as painful as it was before surgery. Medicine and home care can help.

Post-procedure Care

At the Care Center

Right after the procedure, the staff may:

  • Give you pain medicine
  • Show you how to care for the area
  • Teach you how to make bowel movements less painful
Preventing Infection

During your stay, staff will take steps to lower your chance of infection, such as:

  • Washing their hands
  • Wearing gloves or masks
  • Keeping your incisions covered

You can also lower your chance of infection by:

  • Washing your hands often and reminding visitors and staff to do the same
  • Reminding staff to wear gloves or masks
  • Not letting others touch your incisions
At Home

It will take 6 weeks for the incision and muscles to fully heal. Physical activity may need to be limited during recovery. You may need to delay your return to work for up to 2 weeks.

Call Your Doctor

Call the doctor if you are not getting better or you have:

  • Signs of infection, such as fever and chills
  • Excessive swelling in the rectal area
  • Large amounts of bleeding from the rectum
  • Foul-smelling drainage from the rectum
  • Problems controlling bowel movements
  • Problems urinating

If you think you have an emergency, call for medical help right away.


American Society of Colon and Rectal Surgeons 

Family Doctor—American Academy of Family Physicians 


Canadian Society of Colon and Rectal Surgeons 

The College of Family Physicians of Canada 


Anal fissure. EBSCO DynaMed website. Available at: Accessed October 20, 2020.

Anal fissure expanded information. American Society of Colon and Rectal Surgeons website. Available at: Accessed April 3, 2018.

Anal fissures. Cleveland Clinic website. Available at: Accessed October 20, 2020.

Anal fissures. UCSF Medical Center website. Available at: Accessed October 20, 2020.

Anal fissure treatments. University of Wisconsin School of Medicine and Public Health, UW Health website. Available at: Accessed October 20, 2020.

Higuero T. Update on the management of anal fissure. J Visc Surg. 2015 Apr;152(2 Suppl):S37-43.

Revision Information