For both men and women, colorectal cancer is the third deadliest cancer there is. This is why it's so important to get screened for it. As with all cancers, the earlier it's found, the easier it is to fight off. So you need to know what to look for and what doctors do to screen for colorectal cancer. Here are the common signs and symptoms of colorectal cancer and the screening methods used to determine if you have it.

Signs and Symptoms of Colorectal Cancer

If you have any of these symptoms you should see your doctor.

- Constipation, diarrhea, or any change to the stool that lasts for more than a few days
- Rectal bleeding or blood in the stool
- Feeling like you have to have a bowel movement, but when you do go you are not feeling relieved
- Abdominal pain or cramping that is persistent. Gas or pain of any kind that doesn't go away
- Weakness and fatigue
- Weight loss when you weren't trying to lose weight

These symptoms can generally be explained away as other things such as a virus, infection, hemorrhoids, and inflammatory bowel disease. It's important to see your doctor if these issues persist so these things can be ruled out.

There are often no early symptoms of colorectal cancer. Signs and symptoms may vary when it develops depending on where in the colon the cancer is located. You should be more concerned if you are over the age of 50 or have a family history.

Tests for Colorectal Cancer

If you present with any of the above symptoms, then your doctor will take a complete family history. He or she will feel your belly to see if he feels any masses. He might order some blood tests to see what exactly is going on, like a CBC (Complete Blood Count) to check for anemia, and liver enzymes to check your liver function because colorectal cancer can spread to your liver and tumor markers in someone who already has colorectal cancer or has had it.

If symptoms or the results of these tests suggest cancer, then further testing is recommended. This is usually a colonoscopy, but sometimes a sigmoidoscopy or an imaging test that uses a barium enema and a lower GI series. This helps doctors screen for polyps.

During a colonoscopy, if colorectal cancer is suspected the doctor will take a biopsy which is just a small piece of tissue that is removed for further examination under the microscope. In very rare cases, part of the colon may need to be surgically removed (a part less often used) to make the diagnosis.

Additionally, scans such as a CT scan might be performed. This is used more often to see if colon cancer has spread to other organs like the liver. It gives a detailed image of the soft tissues of the body.

An ultrasound might be performed to try to see tumors, but really all this would show is tumors in the liver, gallbladder, or pancreas. It cannot detect tumors in the colon. For that, your doctor might recommend an endorectal ultrasound where a special transducer is inserted into the rectum. This way the doctor can see deep into the rectal wall to see where cancer has spread, if at all, and it can look at the lymph nodes and nearby organs.

If you don't have any symptoms of colorectal cancer but are of a certain age or have a family history, there are screening tests that can be done. Tests that find both colorectal polyps and cancer are perfect. This way if polyps are found they can be removed during the screening to help prevent them from turning into cancer. For less invasive screening, tests that check the stool can be used. However, this doesn't find polyps.  

The colonoscopy is the most common test performed to screen for polyps and cancer. However, the CT scan and the barium enema are used to screen for polyps and cancer as well.

To screen just for cancer, tests like the Fecal Occult Blood test are used. Fecal matter is screened for occult blood which cannot be seen with the naked eye. If there is blood in the stool, a colonoscopy would need to be performed to determine where exactly the bleeding is coming from.

Check with your doctor to see what he recommends based on your symptoms or lack thereof and your family history. While colorectal cancer is the third leading deadly cancer, the development of tests and screenings has been increasing the survival rate.