Transanal Endoscopic Microsurgery (TEMS)

Transanal endoscopic microsurgery (TEM) is a procedure to treat rectal tumors and other problems without making any incisions. Instead, your surgeon inserts microsurgical tools through your anus. TEM has a lower risk of complications and is less painful than open surgery.


What is transanal endoscopic microsurgery?

Transanal endoscopic microsurgery (TEM) is a procedure to treat rectal problems like tumors. Your surgeon inserts small tools through your anus (butthole) to reach your rectum (the lower part of your large intestine). There are no surgical incisions, so you recover quicker and with less pain than in open surgeries.

TEM allows your surgeon to reach rectal tumors high in your rectum. In the past, surgeons could only reach these tumors with open abdominal surgery. Open abdominal surgeries use a large belly incision and can cause long, painful recoveries.


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What is the difference between TEM and TAMIS?

In TEM surgery, your provider inserts a rigid instrument called a rectoscope into your anus. Then they pass small instruments and a camera through the rectoscope.

In transanal minimally invasive surgery (TAMIS), your surgeon inserts a small, gel-like, round port into your anus. They place a small camera and surgical tools through the port. In TAMIS, the camera and tools are the same ones they use during laparoscopic surgeries.

Who is a good candidate for transanal endoscopic microsurgery?

Transanal endoscopic microsurgery may be a good option if you have multiple health conditions or can’t tolerate open surgery. TEM offers a way to remove colorectal cancer without performing open abdominal surgery. TEM is also a useful tool for younger people with early stage or benign (noncancerous) rectal tumors.


Who should not have transanal endoscopic microsurgery?

Not everyone is a candidate for TEM. Because the rectoscope is so rigid, your backbone could block your surgeon’s path to the tumor. In these cases, you may need TAMIS, which uses more flexible tools. People who have a narrowing or stenosis of the anal canal may not be a candidate for TEM or TAMIS.

What does transanal endoscopic microsurgery treat?

Most often, your surgeon uses TEM to remove growths or tumors in your rectum. You may have transanal endoscopic microsurgery to treat:

  • Noncancerous (benign) rectal tumors.
  • Infected passageways in your rectum (fistulas).
  • Rectal cancer.
  • Rectal prolapse.
  • Rectal narrowing (strictures).
  • Small tissue growths (rectal polyps).

Procedure Details

What happens before transanal endoscopic microsurgery?

Preparing for TEM is similar to preparing for a colonoscopy. You need to poop and empty your bowels completely so that your surgeon has a clear view of your rectum. You typically take a laxative to clear your colon and electrolytes to prevent dehydration.

Your healthcare provider will likely instruct you to:

  • Avoid eating solid foods for one day before surgery.
  • Limit your diet to clear liquids only for 12 to 24 hours before surgery.
  • Stop eating and drinking by midnight on the day of your surgery.

Plan to stay home during your bowel prep. Your provider may also instruct you to stop taking certain medications, such as blood thinners, for several days before the procedure.

What happens during transanal endoscopic microsurgery?

You receive general anesthesia so that you stay in a sleeplike state during TEM. In transanal endoscopic microsurgery, your surgeon:

  1. Inserts the rectoscope through your anus and into your rectum.
  2. Fills your rectum with gas to get a clearer view of the tumor.
  3. Places microsurgical instruments and a camera through the rectoscope.
  4. Removes tumors or polyps and a small amount of surrounding tissue.
  5. Stitches your rectal lining back together with dissolvable stitches or metal clips. Your body naturally reabsorbs or expels these stitches as you heal.

What happens after transanal endoscopic microsurgery?

You may feel some discomfort immediately after the procedure. In the first 24 hours after surgery, you may have a:

  • Hollow tube (catheter) in your bladder to drain urine.
  • Intravenous (IV) line in one of your veins to give you fluids.
  • Intravenous (IV) antibiotics for 24 hours.

You can begin eating and drinking within a day after surgery. You may stay in the hospital for one to two days after transanal endoscopic microsurgery.

Care at Cleveland Clinic

Risks / Benefits

What are the advantages of transanal endoscopic microsurgery?

Transanal endoscopic microsurgery allows colorectal surgeons to reach higher parts of your rectum without making an abdominal incision. In the past, these tumors required extensive abdominal surgery. These invasive procedures can have long-term side effects, including bladder problems, erectile dysfunction and permanent colostomy.

In contrast, TEM is typically painless and offers multiple benefits, like:

  • Less bleeding.
  • A lower risk of infection, bowel obstruction and other complications.
  • A shorter hospital stay.
  • A quicker recovery.

What are the risks or complications of transanal endoscopic microsurgery?

Transanal endoscopic microsurgery has lower complication rates than open abdominal surgery. However, there’s a small risk of:

Recovery and Outlook

What is the recovery time after transanal endoscopic microsurgery?

You can get up and move around on the same day as your procedure. After you return home, you can resume your usual activities as you feel able, usually within a day or two.

You may have liquid bowel movements for several weeks after TEM. If needed, you may work with a nutritionist or dietitian to adjust your diet until your bowel function returns to normal.

When to Call the Doctor

When should I see my healthcare provider?

See your healthcare provider if you experience any complications after TEM, like:

  • Bleeding.
  • Difficulty urinating.
  • Fever or chills.
  • Severe abdominal or rectal pain.

Additional Common Questions

Is transanal endoscopic microsurgery the only treatment I need for rectal cancer?

Your healthcare provider may recommend TEM for early-stage rectal cancer. For many people, the procedure successfully removes the tumor, and you don’t need any other treatments. However, some people also need other cancer treatments, such as chemotherapy or radiation therapy, in addition to TEM.

A note from Cleveland Clinic

Finding out you have a tumor can be scary. You may start thinking about the pain and long recovery associated with surgery. With transanal endoscopic microsurgery, your surgeon can remove rectal tumors without making any incisions, so you recover quicker and with less pain. Instead of making a long abdominal incision, your surgeon inserts special instruments through your anus. TEM is a safe, minimally invasive procedure with low complication rates.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 05/03/2023.

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