Skip Navigation
Search Menu
Articles & Answers

Ask the Expert

Colon Cancer: Diagnosis and Staging

Print This Page
What you should know about colon cancer diagnosis and staging

"Is it cancer?" If your gastroenterologist has recently found — and removed — a suspicious-looking polyp during your colonoscopy, you likely have many questions as you await definitive test results.

Many polyps aren’t cancerous. For the ones that are, effective treatment options are available to remove cancerous growths and target symptoms so you can feel better and live a full life.

Prompt treatment for colon cancer is your best chance for recovery. Here’s what Johns Hopkins gastroenterologist Reezwana Chowdhury, M.D., wants you to know about the first steps of colon cancer diagnosis and staging.

Colon Cancer Diagnosis: Getting a Colonoscopy

Most colorectal cancers start as colon polyps, abnormal growths in the wall of the colon. Some polyps can develop into cancer if left untreated for a long time (usually at least 10 years).

Screening is crucial for cancer detection because most colorectal cancers don’t cause symptoms in the early stages. Many times, doctors first spot colon cancer during a routine screening colonoscopy. During a colonoscopy:

  1. Your gastroenterologist uses a flexible tube with a camera at the end to look at the insides of your colon. (You are given a sedative before the procedure so you are relaxed and comfortable.)
  2. If any colon polyps are found, doctors can remove them during the procedure.

Doctors currently recommend most people get a colonoscopy starting at age 50. If your doctor doesn’t find any polyps, you likely won’t need another screening for 10 years.

Colon Cancer Diagnosis: Unusual Symptoms

Other times, your doctor might order a colonoscopy or other test (such as a CT scan) to investigate certain symptoms that could point to colorectal cancer.

The most common sign of colon cancer is bowel changes. Although many other, often routine, health issues can cause bowel changes, please see your doctor for a thorough evaluation if you experience:

  • A change in bowel habits (suddenly becoming constipated, for example)
  • Rectal bleeding
  • Dark stools, or blood in your stools

Colon Cancer: How Doctors Stage Colon Cancer

If your gastroenterologist determines a colon polyp is cancerous, you may need additional imaging tests such as a CT scan to confirm and possibly stage the cancer.

Staging refers to how far a cancer has spread. This will also help determine your treatment.

  • Stage 1 and 2 colon cancer: Confined to the colon wall
  • Stage 3 colon cancer: Has spread to nearby lymph nodes
  • Stage 4 colon cancer: Has spread to distant organs, such as the liver or lungs

Doctors often recommend surgery for colon cancer treatment, explains Chowdhury. While surgery may be an effective treatment for many with colorectal cancer, it is important to seek out an experienced physician for your own case. 

You May Also Like

Doctor explains what patient should expect during colon cancer surgery

Colon Cancer Surgery: What to Expect

A primer on surgery for colon cancer: A Johns Hopkins surgeon shares what to expect and offers tips for recovery.

Colon Cancer Treatment: Your Doctor will consider the location, size and number of lesions before determining treatment

Colon Cancer Treatment: What to Know About Surgery

Here's what else Johns Hopkins colorectal surgeon Bashar Safar wants you to know about surgery to treat colon cancer.

Doctors recommend most healthy people get a colonoscopy at age 50. If nothing abnormal is found, you can probably wait 10 years before your next one.

Colon Cancer: Q&A with a Gastroenterologist

What is the prep for a colonoscopy? Are there other types of colon cancer screening? Read on for expert answers to these and other common questions about colon cancer.