Bowel Polyps
A bowel polyp (otherwise known as a colon polyp) is a small clump of cells that forms on the lining of the colon. Most bowel polyps are harmless. But over time, some polyps can develop into colon cancer, which may be fatal when found in its later stages.
Anyone can develop colon polyps. You're at higher risk if you're 50 or older, are overweight or a smoker, or have a personal or family history of bowel polyps or colon cancer.
Bowel polyps often don't cause symptoms. It's important to have regular screening tests, such as a colonoscopy, because polyps found in the early stages can usually be removed safely and completely. The best prevention for colon cancer is regular screening for and removal of polyps.
Symptoms
Because most people with polyps do not experience any symptoms, you might not know you have a polyp until your doctor finds it during an examination of your colon.
However, some people with colon polyps may experience:
When to see a doctor
See your doctor if you experience:
You should be screened regularly for polyps if:
Causes
Healthy cells grow and divide in an orderly way. Mutations in certain genes can cause cells to continue dividing even when new cells aren't needed. In the colon and rectum, this unregulated growth can cause polyps to form. Polyps can develop anywhere in your large intestine.
There are two main categories of polyps, nonneoplastic and neoplastic. Nonneoplastic polyps include hyperplastic polyps, inflammatory polyps and hamartomatous polyps. Nonneoplastic polyps typically do not become cancerous.
Neoplastic polyps include adenomas and serrated types. These polyps have the potential to become cancer if given enough time to grow. Most of these colon polyps are called adenomas. Serrated polyps may also become cancerous, depending on their size and location in the colon. In general, the larger a polyp, the greater the risk of cancer, especially with neoplastic polyps.
Risk factors
Factors that may contribute to the formation of colon polyps or cancer include:
Hereditary polyp disorders
Rarely, people inherit genetic mutations that cause colon polyps to form. If you have one of these genetic mutations, you are at a much higher risk of developing colon cancer. Screening and early detection can help prevent the development or spread of these cancers.
Hereditary disorders that cause colon polyps include:
Complications
Some colon polyps may become cancerous. The earlier polyps are removed, the less likely it is that they will become cancerous.
Prevention
You can greatly reduce your risk of colon polyps and colorectal cancer by having regular screenings. Certain lifestyle changes also can help:
Diagnosis & Treatment
Diagnosis
Screening tests play a key role in detecting polyps before they become cancerous. These tests can also help find colorectal cancer in its early stages, when you have a good chance of recovery.
Screening methods include:
• Colonoscopy, the most sensitive test for colorectal polyps and cancer. If polyps are found, your doctor may remove them immediately or take tissue samples (biopsies) for analysis.
• Virtual colonoscopy (CT colonography), a minimally invasive test that uses a CT scan to view your colon. Virtual colonoscopy requires the same bowel preparation as a colonoscopy. If a polyp is found during the CT scan, you'll need to repeat the bowel preparation for a colonoscopy to have the polyp examined and removed.
• Flexible sigmoidoscopy, in which a slender tube with a light and camera is inserted into your rectum to examine the last third of your colon (sigmoid) and rectum. The majority of the colon is not examined with this screening test, so some polyps and cancers may not be discovered.
• Stool-based tests. This type of test works by checking for the presence of blood in the stool or assessing your stool DNA for evidence of a colon polyp or cancer. If your stool test is positive you will need a colonoscopy soon afterward.
Treatment
Your doctor is likely to remove all polyps discovered during a bowel examination. The options for removal include:
• Removal with forceps or a wire loop (polypectomy). If a polyp is too large to remove with this method, a liquid may be injected under it to lift and isolate the polyp from surrounding tissue so that it can be removed.
• Minimally invasive surgery. Polyps that are too large or that can't be removed safely during screening are usually removed surgically, which is often performed by inserting an instrument called a laparoscope into the abdomen to remove the diseased portion of the bowel.
• Colon and rectum removal (total proctocolectomy). If you have a rare inherited syndrome, such as FAP, you may need surgery to remove your colon and rectum to protect you from developing a life-threatening cancer.
Some types of colon polyps are more likely to become cancerous than others. A doctor who specializes in analysing tissue samples (pathologist) will examine your polyp tissue under a microscope to determine whether it is potentially cancerous.
Follow-up care
If you have had an adenomatous polyp or a serrated polyp, you are at increased risk of colon cancer. The level of risk depends on the size, number and characteristics of the adenomatous polyps that were removed.
You'll need follow-up screenings for polyps. Your doctor is likely to recommend a colonoscopy:
• In 5 to 10 years if you had only one or two small adenomas
• In 3 to 5 years if you had three or four adenomas
• In three years if you had 5 to 10 adenomas, adenomas larger than 10 millimetres, or certain types of adenomas
• Within six months if you had multiple adenomas, a very large adenoma or an adenoma that had to be removed in pieces
Preparing for your colonoscopy
It's very important to fully prepare (clean out) your colon before a colonoscopy. If stool remains in the colon and obstructs your doctor's view of the colon wall, you will likely need a follow-up colonoscopy sooner than usual to ensure that all polyps are discovered.
After a good colon preparation, bowel movements should appear as clear liquid, which may be slightly yellow or green-tinged, depending on the colour of any liquids consumed during the preparation. If you experience trouble with your colon preparation or feel that you have not been cleaned out by the preparation, you should discuss this with your doctor before beginning your colonoscopy, as some people require additional steps in preparation before attempting colonoscopy.
Care at Chartwell Hospital
At Chartwell Digestive Health we have a team of experienced gastroenterology specialists, dedicated to providing the best possible care for all of our patients.
Our doctors use the most advanced techniques available to find colon polyps. At Chartwell Digestive, colon polyps are usually removed when they are found or later that day, sparing you an extra trip to the clinic and another round of bowel preparation.
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