Symptoms
Include:
- Having diarrhea or constipation
- Feeling that your bowel does not empty completely
- Finding blood (either bright red or very dark) in your stool
- Finding your stools are narrower than usual
- Frequently having gas pains or cramps, or feeling full or bloated
- Losing weight with no known reason
- Feeling very tired all the time
- Having nausea or 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 to 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 you have screening test results that suggest cancer or you have symptoms, your doctor must find out whether they are due to cancer or some other cause. Your doctor asks about your personal and family medical history and gives you a physical exam. You may have one or more of the tests described in the “Screening” section.
If your physical exam and test results do not suggest cancer, your doctor may decide that no further tests are needed and no treatment is necessary. However, your 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.
Source: The Web site of the National Cancer Institute (http://www.cancer.gov)