What is lateral internal sphincterotomy?

Lateral internal sphincterotomy is surgery to help heal an anal fissure that has not improved with medicine or other treatments. An anal fissure is a tear in the lining of the anus.

During the surgery, the doctor puts a lighted tube (called an anoscope, or scope) into the anus. The doctor is able to see the inside of the anus through the scope. Special surgical tools are guided through the scope into the anus. The doctor uses the surgical tools to make a cut (incision) in the internal anal sphincter. The internal anal sphincter is a ring of muscle that controls the anus. This surgery relieves the pressure and allows the anal fissure to heal.

This surgery may be done while you are completely asleep or while you are awake. If you are awake, you will be given medicine to help you relax. You will not feel pain. The surgery usually takes less than 30 minutes. Most people go home the same day.

Many people notice that the pain from their anal fissure goes away within several days after surgery. But it will probably take about 6 weeks for your anus to completely heal. You will probably be able to go back to work and your usual activities about 1 to 2 weeks after surgery.

What happens on the day of surgery?

• Follow the instructions exactly about when to stop eating and drinking, or your surgery may be cancelled. If your doctor has instructed you to take your medicines on the day of surgery, please do so using only a sip of water.
• Take a bath or shower before you come in for your surgery. Do not apply lotions, perfumes, deodorants, or nail polish.
• Remove all jewellery, piercings, and contact lenses.
• Leave your valuables at home.

The day before surgery

• You may need to empty your colon with an enema or laxative. Your doctor will tell you how to do this.

At the hospital or surgery centre

• 
  Bring a picture ID.
• Before surgery you will be asked to repeat your full name, what surgery you are having, and what part of your body is being operated on. The area for surgery may be marked.
• A small tube (IV) will be placed in a vein, to give you fluids and medicine to help you relax. Because of the combination of medicines given to keep you comfortable, you may not remember much about the operating room.
• You will be kept comfortable and safe by your anesthesia provider. The anesthesia may range from making you fully asleep, to simply numbing the area being worked on. This will depend on the procedure you are having, as well as a discussion between your doctor, the anesthesia provider, and you.
• The surgery will take about 30 minutes.
• As you wake up in the recovery room, the nurse will check to be sure you are stable and comfortable. It is important for you to tell your doctor and nurse how you feel and ask questions about any concerns you may have.

Going home

• 
  Be sure you have someone to drive you home.
• For your safety, you should not drive until you are no longer taking pain medicines and you can move and react easily.
• Arrange for extra help at home after surgery, especially if you live alone or provide care for another person.
• You will be given more specific instructions about recovering from your surgery, including activity and when you may return to work.