Colonoscopy and Biopsy for Bowel Cancer

A colonoscopy is a test that allows a doctor to look inside the large bowel using a flexible tube with a camera. If an abnormal area is seen, a small tissue sample may be taken. This sample is called a biopsy.

This article is for general information only. Your doctor or endoscopy team can explain why colonoscopy and biopsy are recommended in your case.

What Is a Colonoscopy?

Colonoscopy examines the inside of the colon and rectum. It may be used to investigate symptoms, follow up an abnormal stool test, remove polyps or help diagnose bowel cancer.

Cancer Research UK explains that colonoscopy is usually done as an outpatient test in an endoscopy department, and preparation instructions are given before the appointment. :contentReference[oaicite:3]{index=3}

What Is a Biopsy?

A biopsy is a small sample of tissue taken from an abnormal area. The sample is sent to a laboratory where specialists look at it under a microscope.

A biopsy can help confirm whether cancer cells are present and may provide information needed for treatment planning.

Why Colonoscopy and Biopsy May Be Needed

These tests may be recommended if you have symptoms such as blood in the stool, persistent bowel changes, anaemia, unexplained weight loss or abnormal screening results.

If a stool-based screening test is abnormal, follow-up colonoscopy may be needed to complete the screening process. CDC notes that abnormal results from stool tests, flexible sigmoidoscopy or CT colonography need colonoscopy to complete screening. :contentReference[oaicite:4]{index=4}

Preparing for Colonoscopy

You will usually need bowel preparation before the test. This may involve changing your diet, drinking clear fluids and taking prescribed laxatives.

For more detail, read our Bowel Preparation Before a Colonoscopy guide.

What Happens After the Test?

After colonoscopy, you may feel bloated or pass wind. If a biopsy or polyp removal was done, you may notice a small amount of bleeding. Your clinic will tell you what symptoms are expected and what symptoms need urgent advice.

Biopsy results may take time. Ask when and how you will receive the results.

Final Thoughts

Colonoscopy and biopsy can provide important information when bowel cancer is suspected. Ask your healthcare team why the test is needed, how to prepare and what the results may mean.

For more testing information, visit our Tests to Find Cancer in the Bowel article.