If you experience symptoms similar to those of colorectal cancer (see colorectal cancer symptoms), it is important to see your doctor as soon as possible. Colorectal cancer can be cured in more than 9 out of 10 cases when it is diagnosed early.
Physical exam – to start the diagnosis, your doctor will ask you questions about your medical history and the symptoms you experience. It is important that you detail all the symptoms and the time they occur. Tell your doctor all recent changes happening in your digestive system. If the examination reveals suspicion of colorectal cancer, you will be recommended a stool test.
Stool test – unlike many other cancers, colorectal cancer can be detected early by less complicated examinations. Although simple, the stool test can help your doctor detect presence of blood in your stool. In fact, even without signs of colorectal cancer, this test can also be performed every two years as a means of screening for men and women aged 50 to 74 years. In case of a positive result, other tests such as rectal examination, colonoscopy, sigmoidoscopy, barium enema, ultrasound and CT scan will be performed to confirm the presence of the cancer in your intestine.
Digital rectal examination (DRE) – during a DRE, your doctor inserts a gloved finger into your rectal cavity searching for abnormalities; the test sometimes helps to identify a tumor in the rectum. Digital rectal exam is painless; however, some patients find it uncomfortable. In addition, a digital rectal examination cannot confirm the existence of colorectal cancer; other medical techniques such as colonoscopy, barium enema and sigmoidoscopy will be performed.
Sigmoidoscopy – this invasive medical procedure allows your physician to examine the lining of your rectum and lower colon, using a sigmoidoscope – a hollow tube with a camera on the end. During the procedure, your health care provider inserts the sigmoidoscope through the rectuminto the terminal section of the large intestine (sigmoid colon) to visualize and analyze it. In case growths (polyps) are found, samples will be removed to be examined under microscope to look for cancer cells (biopsy).
Barium enema – this radiological examination allows your doctor to visualize your lower gastrointestinal (GI) segment and confirm presence of polyps after filling the colon with a contrast material containing barium. During the procedure, the specialist injects the barium into your colon through a small tube placed in your anus. The barium travels throughout the colon and lining its walls in order to make them clearly visible on the X-ray picture. This is a quick and painless test; however, it is less and less performed since the generalization of colonoscopy.
Colonoscopy – this technique allows the visualization of the inside of the colon in its entire length using a flexible fiber optic. During the exam, your physician inserts through your rectum a flexible tube with a light called endoscope. Unlike barium enema, colonoscopy allows your doctor to perform a biopsy of the tumor and removal of any polyps.
Other tests – these days, other tests such as ultrasound and computed tomography (CT) are used in the diagnosis of colorectal cancer. These techniques allow your doctor to determine the stage of the cancer, and detect if it has spread to other organs (metastatic colorectal cancer) such as the liver.