Polyps are a type of abnormal growth on the inner lining of your colon (large intestine) and rectum. They can range in size from a few millimetres to several centimetres. They often do not cause any symptoms but can increase your risk of developing bowel cancer.
Your risk of colorectal polyps depends on a number of factors including your age, family history and medical conditions. Your doctor can use a stool test, blood tests and a CT scan to check your colorectal health.
The shape of the polyp is also important to your diagnosis. Some polyps are flat or slightly raised (sessile) while others are raised on a stalk, called pedunculated. These types of polyps can vary in color and size.
Most polyps are benign but some types called adenomas may become precancerous over time. Adenomas are the most common form of polyps, making up about two-thirds of colorectal polyps and leading to bowel cancer in many cases.
Adenomatous polyps are histologically classified as tubular, villous or tubulovillous – each of these has a distinct growth pattern that increases the likelihood of cancer. Most small adenomas have a tubular growth pattern, but some larger ones have a villous pattern.
These are considered the most dangerous polyps. They are less likely to be removed by a doctor than other types of polyps, and may lead to bowel cancer over time.
Hyperplastic polyps, which are rarer than adenomatous polyps, are less likely to develop into cancer. They are smaller than adenomatous polyps and have a flat or oval shape, but they may grow in size until they block the flow of stools. They may also have a serrated or sawtooth appearance with goblet cells and mucin droplets.
They are more prone to bleeding and have an increased risk of forming ulcers or becoming irritated. They can also cause changes in your bowel habits and anaemia, low blood levels.
Symptoms and Treatment for Polyps
If polyps are discovered during screening, they are removed (polypectomy) to prevent them from turning into a type of cancer called bowel cancer. Your doctor may also take a sample of the polyp (biopsy) to find out more about its microscopic type.
Polyps are usually spotted during a routine colonoscopy, a procedure in which a thin tube with a camera is placed through the rectum into your large intestine to examine it for any signs of abnormality or cancer. If the doctor detects a polyp, they will remove it and send the sample to the lab for analysis.
The results of the biopsies can help determine whether you should be referred for a repeat screening. Your doctor will recommend a schedule of screenings based on the number and size of your polyps as well as your other risk factors.
Screenings for colorectal polyps and bowel cancer are important to improve your chances of survival. They can be done by a doctor using a simple method, such as stool testing, or by a more complicated procedure, such as a colonoscopy or sigmoidoscopy.
