The colon and rectum make up the large intestine (or large bowel). The colon absorbs water and salt from food after it goes through the small intestine (small bowel). The intestines are part of the digestive system, also called the gastrointestinal (GI) system.
Once food goes through the colon, waste is left. This waste moves through the rectum, also part of the digestive system.
Colorectal cancer often begins as a growth of extra tissue, called a polyp, inside the colon or rectum. Over time, some polyps may grow and turn into cancer.
Tumors are cancerous or noncancerous growths that form when too many cells grow. When too many cancer cells grow in the colorectal area, a cancerous tumor can form.OR
Colorectal cancer is often called a silent disease because it grows without any symptoms.
If you do have symptoms, they may include:
- Blood in or on the stool
- Change in bowel habits
- Stools that are narrower than usual
- General stomach discomfort, such as bloating, fullness or cramps
- Diarrhea, constipation or feeling that the bowel does not empty completely
- Frequent gas pains
- Weight loss without trying
- Bleeding from the rectum
- Feeling tired a lot or feeling tired during an activity that you used to do without any problem
If you have any of these symptoms for more than two weeks, see your doctor right away. These symptoms can happen for other reasons besides cancer. If you have symptoms like those listed above, you should talk to your provider to find out the reason.OR
There are many ways your doctor may find colorectal cancer. Your doctor may also do one or more of the following:
- A fecal occult blood test that can find hidden blood in the stool
- A double contrast barium enema and X-ray, where liquid is put in the rectum before an X-ray so doctors can see any abnormal growths in the colon
- A digital rectal exam or when a doctor can feel for any abnormalities inside the lower rectum, pelvis and lower belly
Sometimes more exams that use a tube that bends easily with a lens at the end are needed. Those exams are called:
- A colonoscopy to see inside the large intestine
- Flexible sigmoidoscopy to see inside the lower part of the colon
Colorectal cancer is the third leading cause of cancer-related deaths in the United States for both men and women.OR
The chances of getting colorectal cancer go up as people age. It's more common in people age 45 and older.
You also have a greater chance of getting colorectal cancer if you have a personal history with these medical problems or if the following medical problems run in your family:
- Inflammatory bowel disease
- Colorectal cancer
- Ovarian cancer
- Endometrial cancer
- Breast cancer
Black Americans have the highest death rates of colorectal cancer in the United States.
Ask your doctor about when you should start getting screenings.OR
If polyps are found during a colonoscopy, you should have them removed. Sometimes these polyps can turn into cancerous growths.
There is no sure way to stop someone from getting colorectal cancer. There are some things you can do to help lower your chances for getting it, such as:
- Have a low-fat diet (eating plan)
- Don't smoke
- Don't drink alcohol
- Watch your body weight and get exercise
Most colorectal cancer is treatable. How we care for colorectal cancer depends on many factors:
- Type of cancer
- Size of the cancer
- Where the cancer is located in the body
- Stage of cancer
Your doctor will work with you to find the right care plan for you. Some examples of treatment include:
- Surgery to remove cancer
- Chemotherapy (using medication to make the cancer smaller or to kill cancer cells)
- Radiation (using X-rays to kill cancer cells)
- Cryosurgery (using cold temperatures to freeze or kill cancer cells)
- Targeted therapy (using drugs to stop cancer cells from growing and spreading)
- Ablation to kill tumors without removing them
- Immunotherapy (using the body’s immune system that naturally fights illness)
- American Cancer Society. Colorectal Cancer Risk Factors. Accessed April 8, 2021.
- Centers for Disease Control and Prevention. Colorectal Cancer Statistics. Accessed April 8, 2021.