Screening
Screening for cancer before a person has symptoms can help the doctor find polyps or cancer early. Finding and removing polyps may prevent colorectal cancer. Also, treatment for colorectal cancer is more likely to be effective when the disease is found early.
To find polyps or early colorectal cancer:
- People in their 50s and older should be screened.
- People who are at higher-than-average risk of colorectal cancer should talk with their doctor about whether to have screening tests before age 50, what tests to have, the benefits and risks of each test, and how often to schedule appointments.
The following screening tests are used to detect polyps, cancer, or other abnormalities in the colon and rectum. The doctor can explain more about each test:
- Fecal occult blood test (FOBT): Sometimes cancers or polyps bleed, and the FOBT can detect tiny amounts of blood in the stool. If this test detects blood, other tests are needed to find the source of the blood. Benign conditions (such as hemorrhoids) also can cause blood in the stool.
- Sigmoidoscopy: The doctor checks inside the rectum and lower (sigmoid) colon with a lighted tube called a sigmoidoscope. If polyps are found, the doctor removes them. The procedure to remove polyps is called a polypectomy.
- Colonoscopy: The doctor examines inside the rectum and entire colon using a long, lighted tube called a colonoscope. The doctor removes polyps that may be found.
- Double-contrast barium enema (DCBE): A DCBE is a series of x-rays of the colon and rectum. The patient is given an enema with a barium solution, and air is pumped into the rectum. The barium and air outline the colon and rectum on the x-rays. Polyps may show up on the x-ray.
- Digital rectal exam (DRE): A rectal exam is often part of a routine physical examination. The doctor or nurse inserts a lubricated, gloved finger into the rectum to feel for abnormal areas in the lower part of the rectum.
The NCI fact sheet, Colorectal Cancer Screening: Questions and Answers, has more information about these screening tests. It is available on the Internet at http://cancer.gov/publications and by calling 1-800-4-CANCER.
People may want to ask the doctor the following questions about screening:
- Which tests do you recommend for me? Why?
- How much do the tests cost? Will my health insurance plan help pay for screening tests?
- Are the tests painful?
- How soon after the tests will I learn the results?
Symptoms
Common symptoms of colorectal cancer include:
- A change in bowel habits
- Diarrhea, constipation, or feeling that the bowel does not empty completely
- Blood (either bright red or very dark) in the stool
- Stools that are narrower than usual
- General abdominal discomfort (frequent gas pains, bloating, fullness, and/or cramps)
- Weight loss with no known reason
- Constant tiredness
- Nausea and vomiting
Most often, these symptoms are not due to cancer. Other health problems can cause the same symptoms. Anyone with these symptoms should see a doctor so that any problem can be diagnosed and treated as early as possible.
Usually, early cancer does not cause pain. It is important not to wait to feel pain before seeing a doctor.
Diagnosis
If a person has any signs or symptoms of colorectal cancer, the doctor must determine whether they are due to cancer or some other cause. The doctor asks about personal and family medical history and may do a physical exam. The person may have one or more of the tests described in the "Screening" section.
If the physical exam and test results do not suggest cancer, the doctor may decide that no further tests are needed and no treatment is necessary. However, the doctor may recommend a schedule for checkups.
If tests show an abnormal area (such as a polyp), a biopsy to check for cancer cells may be necessary. Often, the abnormal tissue can be removed during colonoscopy or sigmoidoscopy. A pathologist checks the tissue for cancer cells using a microscope.
People may want to ask the doctor these questions before having a biopsy:
- How will the biopsy be done?
- Will I have to go to the hospital for the biopsy?
- How long will it take? Will I be awake? Will it hurt?
- Are there any risks? What are the chances of infection or bleeding after the biopsy?
- How long will it take me to recover? When can I resume a normal diet?
- How soon will I know the results?
- If I do have cancer, who will talk to me about the next steps? When?
