Recently, many of my friends have undergone colonoscopy and asked me some questions about colorectal cancer and colorectal polyps.

Colorectal cancer is one of the most common cancers in China, and many colorectal cancers evolve from colorectal polyps. Does this mean that all colorectal polyps need to be removed? What should I pay attention to when excising? Can colonoscopy prevent colorectal cancer and colorectal polyps?

Why are there polyps in the large intestine?

In the large intestine, feces are stored and passed through. Faeces, foreign body irritation, and mechanical damage cause wounds to the mucous membranes. Normal mucosal repair should return to intact, and a few deep wounds will leave scars. However, due to genetic mutations, some patients’ wound repair will produce excessively proliferative cells to form neoplasms, which are generally known as polyps.

Do colon polyps have symptoms?

Colorectal polyps generally have no symptoms, and there will be no special pain and other discomfort, unless the polyp is too large to cause obstruction and volvulus, or long-term bleeding causes anemia, etc.

Does it matter if you have colon polyps?

Depending on the type of colorectal polyp, there are different chances of transforming into colorectal cancer and causing death. Large polyps are also at risk for acute episodes of intestinal blockage and volvulus. Colorectal polyps are relatively easy to bleed, and long-term blood loss may also cause anemia. It is generally believed that small hyperplastic polyps and inflammatory polyps have a very low risk of canceration and are polyps that do not require active treatment; adenomatous or sessile serrated polyps are high-risk polyps, and active treatment is recommended.

Can colorectal polyps become colorectal cancer?

Most will. Depending on the type of polyp, the patient’s genetic variation, and the carcinogenicity of the patient’s large intestine contents, there will be different cancer risks. For an adenoma that is not treated at all, it takes about 10 years on average to accumulate mutations and become cancerous. But high-risk genetic variants can cause cancer in less than a year. The types of polyps that are at risk of becoming cancerous are: sessile serrated polyp, tubular adenoma, tubular villous adenoma, villous adenoma.

Some people ask whether regular defecation can prevent polyps from becoming cancerous, but it can only be said to be helpful, because regular defecation helps excretion of feces and other wastes in the intestines, and avoids the pollution in the intestines leading to polyp inflammatory reaction. However, after polyps appear in most patients, Defecation habits will have an impact, so if you continue to change your bowel habits, it is recommended to go to the hospital for examination.

Can colonoscopy help prevent polyps from becoming cancerous? If polyps are found during the examination, will they be removed by the way?

Colonoscopy currently seems to be one of the best tools to prevent colorectal polyps and colorectal cancer. It is recommended that people over 45 years old should try a colonoscopy. As for people under 40 years old, if they have no symptoms, they can consider fecal occult blood test for early detection. prevention.

If polyps are found during the examination, with the consent of the patient, and the patient’s vital signs are stable, after the doctor evaluates the risk of cancer and complications, small polyps can be treated on the spot. If it is a low-risk polyp, the patient has not consented, the on-site equipment is insufficient, the large intestine environment is too dirty, the patient’s vital signs are unstable, and the polyp is too high-risk after resection, generally, it will not be done immediately, but will be reserved for the examination and then at an appointed time. .

How to remove colorectal polyps? Will there be complications?

In addition to traditional surgery and laparoscopic surgery, endoscopic surgery is the preferred choice for polyp resection. Doctors use a thin instrument to remove the polyp by treating the lumen with an endoscope. Complications are bleeding from wounds, infection, perforation of the intestine, instability of the patient’s vitals due to inflation of the intestine, and high concentrations of methane resulting in an explosion in the intestine from the use of electrocautery.

Because there are feces in the large intestine, as well as fermented hydrogen and methane, the bowel should be cleaned thoroughly before examination and treatment to provide a good view and reduce the risk of postoperative infection and intraoperative methane explosion. What everyone needs to understand is that these risks are very small, after all, the colon will be cleaned one day before the colonoscopy.

If the colorectal polyp is benign, can it not be removed? But if it is also removed, is it safer?

Sessile serrated polyps, tubular adenomas, tubular villous adenomas, villous adenomas, etc., are polyps with a risk of cancer, and are strictly benign polyps, but they are so-called precancerous lesions, so it is recommended to remove them . Of course, if the patient is too frail or too old to evaluate the cancerous process after the expected end of life, there is no need for immediate resection.

As for the common hyperplastic polyps, because the risk is very low, resection is only recommended for hyperplastic polyps located in the proximal large bowel, more than 0.5 cm; or located in the distal large bowel, more than 1 cm.

According to an article published by the American Cancer Society in 2017, the use of colonoscopy and the act of removing these potentially cancerous benign polyps can reduce the incidence of colorectal cancer by 40% and the death rate from colorectal cancer by 50%.

How often should a colonoscopy be done after a colon polyp is removed?

Although most colorectal cancers progress in about 10 years, however, considering genetic factors and the patient’s dietary habits, if a close relative has colorectal cancer, even after polyp removal, colonoscopy should be checked every 5 years.

For patients with a history of other polyps, the 2020 American Colorectal Cancer Specialist Association recommends the type and number of polyps to be removed:

Polyp Free: Check After 10 Years

Hyperplastic polyps: Check within 3-10 years (depending on the number and size)

Tubular adenoma, tubular villous adenoma, villous adenoma: 1-10 years of inspection (depending on the number, size, and differentiation)

Sessile serrated polyps: 3-10 years to check (depending on the number and size, whether there is abnormal differentiation)

Of course, if it is a large intestine with poor bowel cleansing, it is recommended to do a colonoscopy within 3 months to 1 year.

If there is more than one polyp, will it be removed as well? How many can be cut?

If it is a polyp that needs to be removed, it will be removed together when the time and equipment are sufficient, and the patient’s vital signs are stable. However, there are many things to consider when removing polyps. For example, for patients with hundreds or thousands of polyps, it is not practical to completely remove them at one time, and the recurrence rate after removal is also high, so other treatment methods should be considered. In addition, if it is expected that the wound after polypectomy is too large or the angle will not be able to be sutured, you should consider staying in the hospital for observation or using other methods, and the problem of inability to stop bleeding may occur if you take action rashly. After the first polyp was cut, it was found that the patient was difficult to stop the bleeding, and the second polyp was not cut immediately, but after the patient’s easy bleeding factors were immediately improved, other polyps were considered to be removed.

Why can’t I take a plane right away after having a colon polypectomy?

The pressure changes in the cabin can make the risk of residual gas in the intestines unknown, which may increase the risk of abdominal pain and bleeding, perforation. Delay the rescue time.

In addition, it is inevitable to carry luggage when going abroad, and the weight-bearing will also increase the abdominal pressure, which will also increase the risk of wound bleeding. This is the reason why patients often bleed at airports after polypectomy.

It is recommended not to travel far for two weeks after polypectomy, because delayed bleeding and perforation may occur during this period, and the risk is too high if the person is in the mountains or abroad at the time.

After the polyp is cut, is it done once and for all?

According to the 2020 data, in the control group with a 10-year cumulative incidence of colorectal cancer of 2.1%, the 10-year cumulative incidence of colorectal cancer in the population of hyperplastic polyps after polypectomy was 1.6%; sessile serrated polyps The 10-year cumulative incidence of colorectal cancer was 2.5%; the 10-year cumulative incidence of colorectal cancer of tubular adenoma was 2.7%; the 10-year cumulative incidence of colorectal cancer of tubular villous adenoma was 5.1%; the 10-year cumulative incidence of colorectal cancer of villous adenoma The annual cumulative incidence rate was 8.6%.

Therefore, we can find that even if we remove the lesion and interrupt the cancerous process there, the patient still cannot recover to the same basic risk as ordinary people, that is to say, other colorectal mucosa is still at risk of cancer.

This is because there are several important factors for the occurrence of colorectal polyps and colorectal cancer: micro wounds, inflammation, genetic variation, environmental carcinogenic factors, time, etc. Removing the lesion cannot change other factors, so even after the polyp is removed, it is necessary to continue to follow up and check and correct bad living and eating habits.

Is the occurrence of colorectal polyps related to diet?

There should be. In addition to genetic variation, polyps should be related to food and the contents of the large intestine. However, the current evidence is relatively sufficient in studies related to colorectal cancer.

Colorectal cancer is currently the cancer with the highest known association with diet, with 38.3% of clinical cases being diet-related, followed by head and neck cancer at 26%.

Foods known to cause colorectal cancer include: cigarettes, alcohol, over-processed sweets, beverages (high fructose, corn syrup), processed and red meat, and even food coloring. Obesity can cause colorectal cancer.

In contrast, foods that reduce the risk of colorectal cancer include: Mediterranean diet, vegetarian or semi-vegetarian diet, whole grains, non-fermented milk, dietary fiber, calcium, cottage cheese, yogurt.