What to Expect From a Colon Biopsy

A colon biopsy is a term used to describe the removal and examination of a tissue sample from the colon. It is a diagnostic procedure used to determine whether any of the tissue cells are cancerous or precancerous.

Having a colon biopsy requested or performed does not mean that you have cancer. It is considered a routine precaution in the same way that a mammogram, Pap smear, or prostate exam is used to screen for breast, cervical, and prostate cancer.

Male patient and doctor in discussion in exam room
Thomas Barwick / Getty Images

Reasons for a Colon Biopsy

Most colon cancer starts as a benign growth called a polyp. Although some polyps look more suspicious than others (because of their color, texture, or size), a biopsy would be performed on each polyp just to be safe. Any other tissue in the colon that looks suspicious will also be screened.

While the biopsy may be part of a routine colon exam, it may be also requested if you are experiencing any of the following symptoms or combination of symptoms:

  • sudden, unexplained weight loss
  • blood in the stool
  • unexpected changes in bowel movement
  • persistent diarrhea
  • chronic abdominal pain

An investigation may also be requested if a fecal occult blood test (FOBT) and/or the fecal immunochemical test (FIT) shows sign of blood in your stool.

How the Procedure Is Performed

A colonoscopy is the standard method for performing a colon biopsy. It involves the use of a four-foot-long, flexible tube, called a colonoscope, which is inserted into the rectum while the person is under sedation. The colonoscope is equipped with a light, a camera, and a specialized device used to snip tissue samples.

Colonoscopy Preparation

A day prior to the procedure, you will be asked to take a strong laxative in order to ensure the bowels are clear of any fecal matter. To some people, this is the most unpleasant part of the procedure since it involves repeated trips to the toilet and sometimes explosive rushes of runny stools or fluid. An enema may also be provided to help remove residual matter. There is little actual pain or discomfort to the cleaning out stage, although minor cramping may occur.

You will also be asked to restrict your diet to things like clear broth and Jello in order to ensure that the colon is completely evacuated and free of any obstructions that can interfere with viewing.

On the day of the procedure, you will be interviewed by an anesthetist who will ask if you have any allergies or prior bad experiences to anesthesia. Once you are prepped and dressed in a hospital gown, you will be laid on your side on the examining table with your knees pulled toward your chest.

The procedure takes anywhere from 20 minutes to one hour.

After the Procedure

While the idea of having a piece of your colon removed may seem unsettling, you'll be happy to learn that most people don't even feel any discomfort. The biopsy is taken from the innermost lining of your colon (called the mucosa) which isn't particularly sensitive to pain.

Once home, you may experience some gas or mild cramping, but typically nothing serious. In some rare cases, however, infection or injury has been known to occur.

Call your healthcare provider immediately if you experience any of the following symptoms:

  • fever or chills
  • heavy bleeding (more than a teaspoon at a time)
  • severe pain or bloating
  • vomiting
  • irregular heartbeats (arrhythmia)

Getting Your Biopsy Results

Once the biopsy is sent the lab, you should expect to receive the results within a week.

If there is cancer, your healthcare provider will schedule other tests to determine how aggressive it is and whether it started in your colon or has spread from other parts of the body. These evaluations will be used to determine the best course of treatment moving forward.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. The American Cancer Society. Tests to Diagnose and Stage Colorectal Cancer. Last revised August 10, 2018.

  2. Cancer Treatment Centers of America. Colorectal Cancer Symptoms.

  3. The American Cancer Society. Colorectal Cancer Screening Tests. Last revised May 30, 2018.

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