Lateral Internal Sphincterotomy

Lateral internal sphincterotomy (LIS) is the name for the surgical operation to make a cut on the sphincter muscle of the anus. LIS is a treatment for anal fissure. More accurately, the main purpose is to help the fissure to heal by itself, by relaxing the sphincter muscle through sphincterotomy.

“Lateral” is the surgical approach to start the incision entry. For some types of surgery, all lateral, posterior and anterior approaches can be used. For sphincterotomy, however, lateral approach is the only method used.

“Internal” refers to the internal sphincter, where the incision is targeted. The cut is often made to the superficial sphincter as this reduces the chance of side effects later.

Despite its rather complex-sounding name, lateral internal sphincterotomy is really a simple surgery to make one small cut to the anal muscle. It generally takes about 20 to 30 minutes to perform. And patients are admitted and discharged on the same day.

Lateral internal sphincterotomy operation itself does not remove skin tag. Anal skin tag can be removed by either ligation or cauterizing. Nevertheless, it is not uncommon to have both sphincterotomy and skin tag removal performed in the same operation.

Other related operation that might be performed with sphinterotomy (depending on the anal fissure conditions) are :

  • hemorrhoidectomy
  • fissurectomy
  • fistulotomy

Again, these operations can be performed together during lateral internal sphincterotomy. You should check with your surgeon the exact name of the operation to be performed. It is a good idea to confirm this with your nurse too, as they are the ones usually checking you into the operation theatre.

Overall, lateral internal sphincterotomy is not a risky procedure and complication rarely happens. Similarly, probability of side effects appears to be low, although there are no official statistics on patients sampling. With the right post-operation care, most patients can expect a full recovery and a normal life again.