April 20, 2024


Outstanding health & fitness


Colonoscopy Q's: How Long & How Often | Stamford Health

Colorectal cancer occurs in the colon and rectum. You have colorectal cancer when there is abnormal cell growth in those two organs. 

What causes colorectal cancer?

According to studies, 95% of colorectal cancers are sporadic, which means that the genetic changes occur once the person is born, so there is no risk of passing them on to the next generation. The other 5% is inherited colorectal cancer and occurs when the gene mutations are passed from one generation to the next. 

Colorectal cancer develops when the DNA cells in the colon and rectum develop mutations that make them grow out of proportion. Often the immune system attacks these mutated cells, and they eventually die. However, some may escape and grow out of proportion forming a tumor in the colon or rectum. The exact cause of colorectal cancer remains unknown, but certain risk factors are linked to the disease.

The importance of colorectal cancer screening

Like any other cancer, colorectal cancer screening is vital to detect the signs of the cancer early and treat it before it worsens. A doctor may detect precancerous polyps through screening, which are easier to treat when detected early. They can develop a suitable screening plant based on your family history and risk factors. Hong Kong colorectal cancer screening options include:

  • Lab tests whereby a sample of stool is examined for traces of blood.
  • Flexible sigmoidoscopy: a doctor inserts a tube with a tiny camera in the rectum to examine it alongside the lower region of the colon.
  • Colonoscopy: a doctor inserts a tube with a tiny camera in the rectum to examine it and the whole colon.
  • CT colonography: This test involves taking images of the whole colon using powerful X-rays and computers.

Risk factors of colorectal cancer

A risk factor is anything that increases your susceptibility to cancer development, but that doesn’t mean that you must get it. Some people with risk factors never develop the cancer, and others may get it even without the risk factors.


The risk of developing colorectal cancer increases with age. That is not to say that young people cannot get the cancer, but the majority of the cases occur in people aged 50years and above. Older adults diagnosed with colorectal cancer also face unique challenges regarding cancer treatment because their immune system is not as strong as it was when they were young. Therefore education, screening, and prevention remain critical.

Family history

You have a higher risk of developing colorectal cancer if you have a first-degree relative who suffered the tumor, for instance, a parent, sibling, or child. You are also susceptible if colorectal cancer cases run in the family; for example, you have an uncle, aunt, nephew, cousin, or niece who had colorectal cancer. Generally, the risk is higher when the family member is diagnosed with the cancer before age 60.

The good news is that only 5% of colorectal cancer cases are inherited. If you have a family history of the cancer, you should talk to a genetic counselor to know whether genetic testing is necessary. Through genetic testing, you can find out whether you have genetic mutations that expose you to developing cancer. A genetic counselor can help you understand the benefits and risks before testing.

Race and ethnicity

In the United States, black people have a high chance of developing sporadic colorectal cancer, which means that the cancer is not inherited. Colorectal cancer cases are highest among non-Hispanic African Americans, and the possibilities are also higher in Jewish people of eastern and central European descent, Alaska natives, and Indian Americans. 

More studies suggest that black women are more likely to die from colorectal cancer than women from other racial groups, although the reasons are unclear. For that reason, black people begin screening with colonoscopies from the age of 45years.

History of polyps or cancer

You have a higher risk of developing colorectal cancer if you were previously diagnosed with colorectal polyps. The susceptibility is higher, especially if the polyps were large and abnormal, even if non-cancerous. The risk is even higher for people previously diagnosed with colorectal cancer.

Polyps are not cancers, but some types of polyps known as adenomas can develop into colorectal cancer. Polyp removal can prevent the risk of developing colorectal cancer, and regular screenings should follow to detect any other signs.

Some genetic syndromes

Some rare inherited conditions can increase your vulnerability to colorectal cancer. They include lynch syndrome, Gardner syndrome, MYH-associated polyposis (MAP), juvenile polyposis syndrome (JPS), familial adenomatous polyposis (FAP), Peutz-Jeghers syndrome (JPS), Muir-Torre syndrome, and Turcot syndrome.

Certain health conditions

Some health conditions are also linked to colorectal cancer. They are inflammatory bowel diseases, including ulcerative colitis and type 2 diabetes. Note that inflammatory bowel disease (IBD) is different from irritable bowel syndrome (IBS). The latter doesn’t increase the risks of colorectal cancer.


Men have a slightly higher rate of getting colorectal cancer than women, but the reasons are unclear.

Diet and food

Recent research links eating more red meat and processed meat to colorectal cancer. You should maintain a healthy diet to prevent such risks.

Physical inactivity

People who are obese and inactive have a higher risk of getting colorectal cancer. It is best to stay active by exercising often and avoiding a lot of sitting.

Prevention or lowering the risks

If you have some risk factors for colorectal cancer, you should inquire and discuss healthy practices with your doctor to lower the risks. There is no way to prevent the cancer, but you can reduce the risks. Regular screening can detect the cancerous polyps early, and the Hong Kong cancer fund can help you carry the financial burden of the treatment.

Polyp removal during a colonoscopy can lower the risk of colorectal cancer. Some studies suggest that NSAIDs may reduce the development of polyps in people exposed to the cancer but should not be a substitute for screening. Taking NSAIDs also comes with some risks.


Knowing the risk factors for colorectal cancer allows you to discuss them with your doctor to make healthy living choices and possibly lower the risks. People with high chances of developing colorectal cancer should regularly consider hong kong colorectal cancer screening to help spot the early signs.