Symptoms | Causes | Risk Factors | Prevention | Diagnosis | Treatment | Next step
Colon polyps are small growths that develop on the lining of the colon (the large intestine). They are very common and on average will affect 1 in 4 people at some point in their lives. Anyone can develop them but they are most common in people over the age of 50 and are slightly more common in men than women.
Whilst most colon polyps are harmless, some can develop into colon cancers over time. Around 2,800 people are diagnosed with bowel cancer in Ireland every year. Bowel cancer is the second most common of all cancers in men and the third most common of all cancers in women in Ireland.
Colon polyps often don’t cause symptoms which is why it is important to have regularcheck ups. If caught in the early stages they can be removed safely and completely but can Be significant is diagnosed in an advanced stage.
Symptoms
Colon polyps often cause no symptoms and you may not even know you have a polyp until your doctor finds it during an examination of your bowel. Some people with colon polyps may experience the symptoms below:
- Bleeding from the rectum - This may be a sign of colon polyps or cancer or perhaps other conditions, such as haemorrhoids or minor tears in your gut lining
- Change in stool colour- Blood can show up as red streaks in your stool or make stool appear black. Change in stool colour may also be associated with other things such as foods, medications and supplements.
- Bowel habit changes - These changes may include frequency, constipation or diarrhoea that lasts longer than a week There are also a number of other conditions that can be the cause of a change in bowel habits.
- Pain - A large colon polyp can partially obstruct your bowel, leading to crampy abdominal pain.
- Iron deficiency anaemia - Bleeding from polyps can occur slowly over time without being visible in your stool. Over time this can result is iron deficiency anaemia, which can make you feel tired and short of breath.
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Causes
Doctors are not sure what actually causes polyps but it is believed that they are caused when mutations in certain genes cause cells to divide when new cells are not needed. This growth in cells can cause polyps to formanywhere in the large intestine.
There are two main categories of polyps, non-neoplastic and neoplastic.
- Non-neoplastic polyps include hyperplastic polyps, inflammatory polyps and hamartomatous polyps - Inflammatory polyps may be associated with ulcerative colitis or Crohn's disease of the colon. Although the polyps themselves are not a significant threat, having ulcerative colitis or Crohn's disease of the colon increases your overall risk of colon cancer.
- Non-neoplastic polyps - these include adenomas and serrated types. Most colon polyps are adenomas. Serrated polyps may 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:
- Age - Most people with colon polyps are 50 or older.
- Inflammatory intestinal conditions - These conditions include ulcerative colitis and Crohn's disease.
- Family history - You are more likely to develop colon polyps or cancer if you have a parent or sibling with them. If many family members have them, your risk is even greater.
- Obesity and lack of exercise.
- Tobacco and alcohol use.
- Type 2 diabetes that isn't well-controlled.
Prevention
- You can greatly reduce your risk of colon polyps and colorectal cancer with regular screening. Certain lifestyle changes also can help to reduce this risk:
- Adopt healthy habits. Include plenty of fruits, vegetables and whole grains in your diet and reduce your fat intake. Limit alcohol consumption and quit tobacco. Stay physically active and maintain a healthy body weight.
- Talk to your doctor about calcium and vitamin D. Studies have shown that increasing your consumption of calcium may help prevent recurrence of colon adenomas. But it isn't clear whether calcium has any protective benefits against colon cancer. Other studies have shown that vitamin D may have a protective effect against colorectal cancer.
- Consider your options if you're at high risk. If you have a family history of colon polyps, consider having genetic counselling. If you've been diagnosed with a hereditary disorder that causes colon polyps, you'll need regular colonoscopies starting in young adulthood.
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.
- Colonoscopy. This is 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). This is a minimally invasive test that uses a CT scan to view the colon. Virtual colonoscopy requires the same bowel preparation as a colonoscopy. If a polyp is found, a colonoscopy will be required to have it removed.
- Flexible sigmoidoscopy. This is where a slender, lighted tube is inserted in your rectum to examine it and the last third of your colon (sigmoid) and rectum. If a polyp is found, you'll need a colonoscopy to have it removed.
- Stool-based tests. This test works by checking for the presence of blood in the stool. If the amount of blood found in your stool sample is above the screening limit, you will need a colonoscopy.
Treatment
Your doctor is likely to remove all polyps discovered during a colonoscopy. The options for removal include:
- Endoscopic removal (polypectomy). If a polyp is larger than 0.4 inches (about 1 centimetre), 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 laparoscopically (key hole surgery)There are certain types of colon polyps that are more likely to become malignant than others. When a polyp is removed it is sent to the lab for testing to determine whether it is potentially cancerous.
Next Steps
If you have signs or symptoms that are worrying you, your first port of call is to talk to your GP. You may be referred to either a gastroenterologist or to General Surgeon for a colonoscopy or other diagnostic test.