A colonoscopy is a medical procedure that allows doctors to examine the inside of your large intestine, including the colon and rectum. This examination uses a long, flexible tube with a camera, called a colonoscope, to detect changes or abnormalities. It plays a significant role in screening for various gastrointestinal diseases, including inflammatory bowel disease and colon cancer.
What Are Colon Polyps?
Colon polyps are small clusters of cells that form on the lining of the colon. While most polyps are harmless, some can develop into colorectal cancer over time. These growths are categorized into two main types: non-neoplastic and neoplastic.
Non-neoplastic polyps, such as hyperplastic polyps, do not become cancerous. Neoplastic polyps, which include adenomas and serrated lesions, have the potential to become cancerous. Most colorectal cancers originate from adenomas, though serrated lesions can also progress to cancer. The larger the neoplastic polyp, the greater the risk of it developing into cancer.
The Process of Polyp Removal During Colonoscopy
Polyps discovered during a colonoscopy are removed during the same procedure, a process known as polypectomy. This procedure is performed by gastroenterologists or colorectal surgeons. The colonoscope, equipped with a camera and light, helps identify the polyps.
For smaller polyps, cold forceps are used to grasp and remove the tissue. For larger polyps, a snare—a wire loop—is used, often with electrocautery (hot snaring) to cut and seal the tissue. In hot snaring, the snare is closed around the polyp, and an electric current is applied to remove it.
Very large or flat polyps may require Endoscopic Mucosal Resection (EMR). EMR involves injecting a solution into the bowel wall beneath the polyp to lift it, creating a cushion that helps protect deeper muscle layers during removal. This allows for the polyp to be removed using a snare. While most polyps can be removed endoscopically, large or complex polyps might require specialized techniques or, if they cannot be safely removed, a separate procedure or surgical intervention.
Why Polyp Removal is Crucial
Removing polyps is an important aspect of preventing colorectal cancer. Many colorectal cancer cases originate from precancerous lesions known as adenomas. Polypectomy interrupts this progression, preventing these growths from developing into cancer.
This makes colonoscopy a procedure that is both diagnostic and therapeutic. It allows for the detection of polyps and their immediate removal, reducing the likelihood of cancer. The proactive removal of precancerous polyps during routine screenings lowers the risk of colorectal cancer.
After Polyp Removal: What to Expect
Following a polypectomy, patients recover from sedation and may experience mild symptoms such as gas, bloating, or slight abdominal discomfort. Some individuals might notice a small amount of blood spotting on toilet paper, which is normal. For larger polyp removals, there is a small risk of bleeding or a perforation in the bowel wall.
The polyps removed during the procedure are sent to a pathology lab for examination. A pathologist analyzes the tissue to determine the type of polyp and whether any cancerous cells are present. This analysis helps confirm if the polyp has been completely removed.
Based on the pathology results, follow-up recommendations are provided for subsequent screenings. The schedule depends on factors such as the number, size, and type of polyps removed. For instance, if one or two small adenomas were found, a follow-up might be recommended in 7 to 10 years. If multiple or larger adenomas were removed, follow-up might be recommended sooner, such as within 6 months to 5 years.