Colorectal Cancer Diagnosis & Detection

Diagnosing Colorectal Cancer

If you have symptoms of colorectal cancer, schedule an appointment to see your doctor as soon as possible. He or she can perform a physical exam and discuss your medical history with you. Your doctor will feel for any unusual lumps or changes in your abdominal region, and examine the rest of your body.

Additionally, your doctor may perform a digital rectal exam. During this simple colorectal cancer detection test, your doctor wears a lubricated glove and uses a finger to check the rectum for any abnormalities. At your appointment, you and your doctor should talk about your next steps and whether you need to undergo additional tests to determine if you have colorectal cancer.

To ensure an accurate colorectal cancer diagnosis, the doctors at Cancer Treatment Centers of America (CTCA) may recommend one or more of the following tests and procedures:

Endoscopic procedures/tests

The gastroenterologists at CTCA use imaging guidance and innovative tools to perform minimally invasive endoscopic procedures and tests that aid in diagnosing colorectal cancer, as well as treating the disease. The procedures/tests below allow our doctors to see inside the colon and rectum.

• Colonoscopy – For this procedure, your gastroenterologist uses a colonoscope, which is a long, flexible and lighted tube with a tiny camera attached to its end. After inserting the colonoscope into the rectum, your gastroenterologist inspects the internal lining of the colon for polyps or other abnormalities. Your gastroenterologist may also perform a biopsy to collect samples of tissues or cells for further investigation.
• Polypectomy (via Colonoscopy) – During a colonoscopy, your gastroenterologist uses a colonoscope to perform this procedure, which involves removing small polyps from the colon or rectum. The polyps are then analyzed in a laboratory to check for cancer.
• Flexible Sigmoidoscopy – For this procedure, your gastroenterologist uses a lighted tube with a tiny camera attached to its end to look inside the rectum and lower part of the colon (i.e., the sigmoid colon) for polyps or cancer sites. He or she may also perform a biopsy to collect samples of tissues or cells for further investigation. This colorectal cancer detection test is an outpatient procedure that does not require pain medication or sedative anesthesia.


Watch a medical animation on video capsule endoscopy.

• Video Capsule Endoscopy – In this procedure, a pill-sized capsule containing a tiny camera allows your gastroenterologist to see approximately 20 feet of the small intestine that cannot be reached with an upper endoscopy or colonoscopy. Once it’s swallowed, the capsule travels through the digestive tract to take thousands of pictures. Using wireless technology, these pictures are transmitted to a small recording device worn on a belt. Your gastroenterologist then studies the pictures to identify potential tumors, as well as sources of bleeding or pain. This procedure is noninvasive and painless, and the capsule takes about eight hours to pass through the system.
• EUS – Endoscopic ultrasound (EUS) helps our doctors make a colorectal cancer diagnosis, stage the disease and determine the best treatment plan for you. The tool’s high-resolution imaging enables your gastroenterologist to carefully examine the digestive tract and nearby organs, including the pancreas, liver, gallbladder and bile duct. This technology helps detect potential tumors and identify lymph nodes in the chest and abdomen to which the cancer may have spread. A very thin needle is used to obtain samples of these tissues, which are analyzed to determine if cancer cells are present.
• Single Balloon Enteroscopy – If a bleeding area or tumor is identified from a video capsule endoscopy, this scope can be introduced into the stomach or colon to enable your gastroenterologist to see the entire small intestine. This allows him or her to take the polyps out of the bowel, biopsy tumors and treat bleeding vessels called arteriovenous malformations.

Laboratory tests

Lab tests, including biopsies and blood tests, aid in diagnosing colorectal cancer, determining the extent of the disease and/or following the progress of treatment.

• Biopsy – Your gastroenterologist performs a biopsy by retrieving polyps and other tissue samples from the colon or rectum during a colonoscopy. The polyps and samples are then sent to a laboratory to be analyzed under a microscope to check for cancer cells. Biopsies are critical to helping our doctors make a colorectal cancer diagnosis.
• CBC Test – Complete blood count (CBC) tests determine the numbers of the different types of cells in the blood. A CBC test can be particularly helpful in determining whether you have too few red blood cells, which causes anemia. This can be a concern for colorectal cancer patients, as they may have a tumor that’s been bleeding for some time.
• Liver Function Tests – These blood tests may be done to assess the function of the liver, an organ to which colorectal cancer can spread.
• Tumor Marker Tests – This blood test may be used in addition to other tests for people who have already been diagnosed with colorectal cancer and are being treated for the disease. The tumor marker tests check for two substances in the blood that colorectal cancer may produce: carcinoembryonic antigen (CEA) and CA 19-9. The tests can help determine the effectiveness of treatment and, sometimes, disease recurrence.

Diagnostic imaging tests

CTCA doctors use various diagnostic imaging tests to detect and pinpoint colorectal cancer and determine the stage of the disease. These tests help our doctors formulate treatment recommendations best suited to you.

• CT – Computed tomography (CT) scans of the chest, abdomen and pelvis are taken to allow doctors to see detailed images of the colon and rectum, as well as the lungs, liver and other organs. CT scans should be taken prior to and at various points throughout colorectal cancer treatment, as the tests help gauge whether treatment is working.
• MRI – Magnetic resonance imaging (MRI) is another imaging tool that may be used in making a colorectal cancer diagnosis. In particular, a pelvic MRI may help doctors stage rectal cancer. MRIs use strong magnetic fields and radio waves to produce exceptionally detailed images. These tests also allow for greater soft tissue contrast than a CT scan.


Learn about the Discovery PET/CT 600 scanner at CTCA.

• PET/CT – This tool merges two diagnostic imaging technologies, positron emission tomography (PET) and CT, into one machine. Patients receive both scans in a single imaging session. PET/CT scans for colorectal cancer are primarily used to help determine the extent to which the disease may have spread. PET/CT should not be routinely used to help gauge whether treatment is working.
• Ultrasound – If there is fluid in your abdomen, your doctor may use this diagnostic tool, which produces images of internal organs from high-energy sound waves and echoes. Our doctors use ultrasound technology to check for tumors in abdominal organs, such as the liver, gallbladder and pancreas.

Advanced Diagnostic Technology & Treatment for Colorectal Cancer

To learn more about the state-of-the-art colorectal cancer detection tests and technology and tools used at CTCA, please call 1-800-615-3055. Or, click to chat. You’ll be connected with one of our Oncology Information Specialists who can answer your questions about CTCA and provide information on our innovative approach to fighting colorectal cancer. You’ll also learn how our cancer hospitals not only have advanced tools for detecting colorectal cancer, but a staff that’s dedicated to turning around test results as quickly as possible and providing patients with a comfortable, stress-free experience.

Next Topic: Colorectal Cancer Staging