Colon polyps are growths in the large intestine (colon). Most of the time, they are discovered during tests designed to screen for colorectal cancer. Typically, colon polyps don’t cause noticeable symptoms unless they become large, leading to bleeding or pain. This is why regular screening is crucial, as it’s often the only way to detect them.
Several effective tests are available to diagnose colon polyps. These tests play a vital role both in screening for colon polyps and colorectal cancer, and in follow-up care after polyps have been removed. These diagnostic methods fall into two main categories: stool tests and tests that visualize the inside of your colon.
Stool Tests for Colon Polyps
These non-invasive tests are designed to detect signs of colon polyps and potential colorectal cancer by analyzing a stool sample. Common stool tests include:
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Fecal Immunochemical Test (FIT): The FIT test is a highly sensitive method used to detect microscopic blood in your stool. Importantly, FIT tests usually do not require dietary restrictions before sample collection, making them convenient. A positive result, indicating the presence of blood, necessitates a colonoscopy to identify the source of bleeding and to remove any polyps found.
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Fecal Occult Blood Test (FOBT): Similar to FIT, the FOBT also checks for blood in the stool, but it is less specific. Unlike FIT, FOBT often requires dietary restrictions before the test to avoid false positives. A positive FOBT result also requires a follow-up colonoscopy to investigate further.
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Stool DNA Test (sDNA/Cologuard): This advanced test analyzes stool DNA to identify specific genetic changes in colon cells that could indicate the presence of polyps or cancer. An abnormal result from a stool DNA test prompts a colonoscopy for a more detailed examination of the colon.
It’s important to understand that an abnormal stool test result does not automatically mean you have colorectal cancer. False positives can occur. However, a positive result signals the need for a colonoscopy to provide a definitive diagnosis. A colonoscopy allows doctors to visually inspect the colon and determine the presence or absence of polyps or cancer.
Tests to Visualize the Colon for Polyp Detection
These procedures provide a direct view of the colon’s interior, allowing for the detection and removal of polyps during the examination. These tests include:
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Flexible Sigmoidoscopy: This procedure uses a flexible, lighted tube with a camera (sigmoidoscope) to examine the lower portion of the colon, specifically the sigmoid colon and rectum. During a sigmoidoscopy, biopsies can be taken of any suspicious growths, and in some cases, precancerous polyps can be removed. If polyps are detected during a sigmoidoscopy, a full colonoscopy is usually recommended to examine the entire colon.
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Colonoscopy: Colonoscopy is the gold standard for colon polyp diagnosis and colorectal cancer screening. It involves using a longer, flexible, lighted tube with a camera (colonoscope) to visualize the entire colon, from the rectum to the cecum. Colonoscopy allows for the detection and removal of polyps throughout the entire colon during the same procedure. Biopsies can also be taken as needed.
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CT Colonography (Virtual Colonoscopy): Also known as virtual colonoscopy, CT colonography uses X-rays and computer technology to create detailed 3D images of the colon. This less invasive test can detect polyps, but if polyps are found, a traditional colonoscopy is still necessary for polyp removal and biopsy.
Follow-Up After Colon Polyp Diagnosis
The type of follow-up required after colon polyp diagnosis depends largely on the type of polyps found and removed during testing.
If biopsies reveal only hyperplastic polyps, which are generally not precancerous, routine follow-up screening according to standard guidelines is typically sufficient.
However, if adenomatous polyps are found (a type of polyp with a higher risk of becoming cancerous), more frequent follow-up colonoscopies are usually recommended. The frequency of these follow-up exams will be determined by factors such as the number and size of adenomatous polyps removed, your age, overall health, and other individual risk factors for colon polyps or colorectal cancer. It’s essential to discuss a personalized follow-up plan with your doctor to ensure appropriate monitoring and care.
It is crucial to have open communication with your healthcare provider about your colon polyp diagnosis and follow-up testing schedule to maintain your long-term health.
