Colorectal Cancer Screening & Diagnosis

We take a proactive approach to cancer screening — especially for high-risk patients — with the goal of catching the disease at an earlier, more treatable stage. An accurate diagnosis is the first step toward treating colorectal cancer.

Screening & Diagnosing Colorectal Cancer

Physicians at the University of Chicago Medicine use a variety of tools and techniques to confirm or rule out the presence of a colorectal malignancy:

• Colonoscopy: A procedure in which a thin tube equipped with a light and camera is inserted into the rectum and colon to look for polyps, cancer or other abnormalities. If you're scheduled for a colonoscopy at UChicago Medicine, learn more about how to prepare for the test.
• Virtual colonoscopy: A noninvasive alternative to colonoscopy used to screen for colorectal cancers. Virtual colonoscopy (VC) uses X-rays and computers to produce three-dimensional images of the rectum, and then displays these images on a screen. Since sedation is not used for virtual colonoscopies, patients can go home after the procedure without the aid of another person and can return to their usual activities right away.
• Fecal occult blood test: A lab test that checks for blood hidden (occult) in a stool sample. If blood is detected, it may be a sign of polyps or cancer in the rectum or colon.
• Ultrasound: A test that uses sound waves to evaluate the depth of cancer and to determine if it has spread to lymph nodes. We offer both endoscopic ultrasound (EUS) and 3D transrectal ultrasound (TRUS). During these procedures, a physician uses a special ultrasound probe to capture images or take tissue samples.
• Probe-based confocal laser endomicroscopy (pCLE): A precise technique for viewing tissue cells in the digestive tract at a cellular level. Using one of the world's smallest microscopes, physicians are able to detect and remove cancerous tissue during a single procedure. In some cases, doctors may send a patient immediately to surgery.

Which Colorectal Cancer Screening Test Is Right for You?

Download our shared decision-making guide (PDF) that can help you work with your healthcare team to decide on the best colorectal cancer test for you. This guide is for adults who are 45 years of age and older who are at average risk for colorectal cancer and do not have a personal or family history of colon cancer or polyps.

PDFs of this decision guide are available in the following languages:

• Arabic
• Chinese (Simple)
• English
• Polish
• Spanish

Staging Colorectal Cancer

After a colorectal cancer diagnosis is confirmed, it's important to determine the extent and size of the cancerous area. This process, known as staging, can help determine the best course of treatment. Some tools used for staging colorectal cancer include:

• Computed tomography scan (CT scan): An imaging study that uses low energy X-rays to evaluate the extent of tumor involvement in the abdomen or pelvis. Our CT scanners that can rapidly produce detailed, three-dimensional images.
• Magnetic resonance imaging (MRI): An imaging study that uses a strong magnet to generate a detailed picture of anatomy. This test is used for staging to evaluate the extent of tumor involvement in the abdomen or pelvis.
• Positron emission tomography scan (PET scan): An imaging study that is sometimes used to stage the extent of disease. Radiolabeled glucose (sugar) is used to assess the location of any abnormally high level of metabolic activity.

Cancer Risk Assessment

The experts in the UChicago Medicine comprehensive cancer risk clinic provide personalized risk assessment – including genetic testing and counseling — for patients and families who are at increased risk of developing colorectal cancer. We work with individuals who have been diagnosed with certain gastrointestinal conditions, including inflammatory bowel disease and polyps, as well as families who have any cancer predisposition syndromes. Learn more about our Gastrointestinal Cancer Risk and Prevention Clinic.