The information on this page was reviewed and approved by
Maurie Markman, MD, President, Medicine & Science at CTCA.

This page was updated on September 9, 2021.

Top questions about colorectal cancer

Colorectal cancer is the fourth most common type of cancer found in American men and women. Here are some questions and answers about the basics of the disease, its symptoms and risk factors.

What you should know about colorectal cancer

Is colorectal cancer the same as colon cancer?

Colorectal cancer is the term used to describe cancer of the colon and/or rectum. The two cancers are grouped together because they share many common characteristics. Together, the colon and rectum make up the large intestine, a question mark-shaped bowel four feet in length. Colon cancer develops in all but the last few inches of the large intestine, between the appendix and rectum. Rectal cancer develops in the rectum, the last few inches of the large intestine that attaches to the anus.

How common is colon cancer?

Colon cancer is more common than rectal cancer. An estimated 95,000 new cases of colon cancer are diagnosed each year, compared to 39,000 cases of rectal cancer, according to the American Cancer Society.

What are the signs and symptoms of colorectal cancer?

Colorectal cancer may develop when benign polyps in the large intestine grow and become cancerous. There may be no early signs or symptoms of benign polyps or colorectal cancer in its earliest stages. As the cancer grows, symptoms may include abdominal pain or cramps; constipation or diarrhea; blood in the stool; bloating or a sense of not feeling empty after a bowel movement; flattened or ribbon-shaped stool and/or pain in the rectum. Signs of advanced colorectal cancer may include unexplained weight loss, fatigue, anemia and loss of appetite.

Is it true that only older men get colorectal cancer?

Your risk of colorectal cancer does increase with age. The median age of a person diagnosed with colorectal cancer is 68. And more men do get colorectal cancer than women. But women also are at risk. In fact, the rate of new cases among men is 47 per 100,000, while the rate for women is 36 per 100,000.

Can colorectal cancer be prevented?

The risk factors for colorectal cancer may be reduced with regular checkups and lifestyle changes. The American Cancer Society recommends that men and women have a colonoscopy beginning at age 50. African Americans have a higher risk of colorectal cancer and should begin screening at the age of 45. If you have a family history of colorectal cancer, you should get screened 10 years earlier than when your family member was diagnosed. For example, if your father was diagnosed with colon cancer at 48, you should talk to your doctor about getting a colonoscopy at 38. Talk to your doctor about how often you should get a colonoscopy. The procedure may be able to help your doctor spot cancer in its early stages. And pre-cancerous polyps may be removed and biopsies performed during the procedure, if necessary. Changes in your lifestyle may also help lower your colorectal cancer risk. Obesity, smoking, alcohol, diet and a sedentary lifestyle have been linked to increased risks for colorectal cancer.

Questions about your colorectal cancer treatment

Treatment for colorectal cancer may depend on the type, location, stage and/or other factors. Here are the answers to some questions about the treatment for colon cancer or rectal cancer:

What are my colorectal cancer treatment options?

Surgery is the most common colorectal cancer treatment. Surgery is used to remove the tumor and surrounding tissue. A portion of the colon or rectum may need to be removed, and a colostomy may be required—permanently or temporarily, depending on the extent of the cancer and how much of the colon or rectum is removed. Other treatment options include chemotherapy and/or targeted therapy drugs, which may also be used in addition to surgery. Radiation therapy is usually an option only for rectal cancer, not colon cancer.

What types of doctors will I see during my treatment?

Your colorectal cancer care team may include one or more of these doctors:

Gastroenterologist, a doctor who specializes in the digestive system (and is most likely to perform your colonoscopy)

Radiation oncologist, a physician who uses radiation therapy to treat cancer

Medical oncologist, a doctor who treats cancer with drug therapies

Surgical oncologist, a doctor who performs surgeries to remove tumors and surrounding tissue or to take tissue samples for biopsies

What's the difference between a colostomy, colonoscopy and the other terms I've seen and heard?

Here is a quick glossary of those terms:

Colectomy: This surgery removes all or part of the colon.

Colostomy: In this procedure, the colon is connected to a hole in the abdomen (called a stoma) to divert stool away from a damaged or surgically repaired part of the colon or rectum. Some colostomies may be reversed once the repaired tissue heals. Other colostomies are permanent, and the tube is attached to a colostomy bag that collects waste.

Colonoscopy: This procedure inserts a flexible, lighted tube with a video camera through the rectum and into the colon. This allows doctors to inspect the lining of the colon for polyps, ulcers, tumors or other abnormalities. Polyps may be removed during the procedure. A colonoscopy may also be used to perform a biopsy.

Colonography: Also known as a virtual colonoscopy, a colonography is a CT scan that uses low-dose radiation to produce an image that may otherwise only be explored via a colonoscopy. During the examination, air may be pumped in to expand the colon for better viewing.

Colitis: This term is used to describe inflammation of the colon.

Is immunotherapy an option for me?

Immunotherapy is not approved specifically to treat colorectal cancer, but it may be prescribed to treat cancers with specific genetic features often found in colorectal cancers. The U.S. Food and Drug Administration has approved the checkpoint inhibitor drug pembrolizumab (Keytruda®) to treat patients with inoperable metastatic tumors that have genetic features called microsatellite instability-high (MSI-H) and/or mismatch repair deficiency. MSI-H mutations are found in about 15 percent of colorectal tumors and in 90 percent of colorectal cancers in patients with Lynch syndrome, a genetic condition that elevates the risk for some cancers.

Questions to ask your doctor

You may have many questions about treatment options for colorectal cancer. Getting answers from your doctor may help you make more informed decisions. Here are some common questions colorectal cancer patients should ask their doctors:

What stage of colorectal cancer do I have?

There are five stages of colorectal cancer. Stage 0, the earliest stage, is used to describe cancer that is confined to the inner lining of the large intestine. Stage 4, the most advanced stage, describes cancer that has metastasized, or spread, beyond the colon to other parts of the body.

What does it mean that my cancer has metastasized?

Colorectal cancer is among several cancers that may travel to other parts of the body—a process called metastasis. In most cases, metastatic colorectal cancer is found in the liver. But it may also spread to the lungs, bones, lymph nodes and central nervous system. Metastatic colorectal cancer presents challenges that may require aggressive surgery, chemotherapy and other treatments. You may also consider talking to your doctor about palliative care to help with symptoms and side effects. Metastatic cancer is different than recurrent cancer, which is cancer that returns to the same part of the body.

What kinds of tests will I need?

A variety of tests may help your doctor determine the stage of your cancer, your cancer type and available treatment options. Tests may include MRIs, CT scans, ultrasounds and other imaging tools. You may also be a candidate for advanced genomic testing, which is used to examine the genomic profile of your cancer's DNA for specific gene mutations that may help your oncologist determine whether specific precision treatment options are available to you.

How will having colorectal cancer affect my quality of life?

This may depend on how advanced your cancer is, if surgery is required and to what extent, and what treatment options are available to you. If caught early, colorectal cancer treatments typically have strong long-term outcomes. Advanced or metastatic colorectal cancer often presents additional challenges. As with all cancers, drug therapies may produce side effects that impact your quality of life. In some cases, surgery may be needed and a colostomy required. Colostomies may be temporary to allow the bowel to heal after surgery. But they may be permanent in cases that require extensive surgery.

Next topic: What are the facts about colorectal cancer?