Colon (Colorectal) Cancer Causes, Symptoms and Prevention

Colon (Colorectal) Cancer Causes, Symptoms and Prevention

Colon cancer is cancer that begins in the large intestine (colon). The colon is the final part of the digestive tract before the rectum.

Colon cancer usually begins as a clump of non-cancerous cells on the inside wall of the colon. The clump of these non-cancerous cells is known as the polyps. Polyps grow over a period of time and convert themselves into cancerous lumps causing cancer.

This might be due to the oncogene activation present in the cells, which earlier was inactivated, but over the period of time, it gets activated due to various chemical, physical or biological factors.

Colon cancer can affect any age group, but older adults are at higher risk. For this reason, the doctor usually recommends screening tests for the detection of colon cancer symptoms so that the polyps can be detected before they turn cancerous.

Colon cancer is often called colorectal cancer, the term in which colon cancer and rectal cancer are combined.

Early Symptoms of Colon Cancer

With the increasing age, the risk of colon cancer also increases. It is better that one starts detection of colon cancer symptoms at an early age. If someone has a family history of colon cancer, then he should consult his physician to start screening tests at an early age.

In many cases, there are no obvious symptoms of colon cancer but below given are some common symptoms that, if noticed, should be discussed with your physician.

  • A drastic change in your bowel habits (loss of appetite)
  • Change in consistency or Diarrhea
  • Blood in stool or rectal bleeding
  • Constipation
  • Abdominal discomfort such as abdominal pain, gas bloating
  • Feeling fatigued constantly
  • Unintentional weight loss

If you notice any of these symptoms frequently, then you should consult your physician for the detection of colon cancer symptoms. Usually, the screening tests begin at the age of 50, but the doctor may recommend you to do the screening tests earlier if you have a history of colon cancer in your family or if you notice any of these symptoms at an early age.

What Causes Colon Cancer?

The primary cause of colon cancer is DNA mutation. The DNA of the cells of the clumps that are the polyps formed on the inner wall of the colon gets mutated and due to this mutation, they cannot stop their division and, as a result, a large clump of cells is formed.

Now oncogene, present in our body in inactivated form, gets activated due to some external factors, and it converts this non – cancerous clump into a cancerous one.

It is not necessary that every time the DNA will mutate itself, and the cells will not stop dividing. This depends on some of the risk factors that are listed below: -

1. Genetics

If a person has a family history of colon cancer or colorectal cancer, then there are chances that he too might have the same. For this, the person needs to consult his physician and ask him to perform screening tests at an early age.

2. Inherited syndromes

Sometimes colon cancer can be inherited as well, or it may bring along other diseases during inheritance. The two most common inherited syndromes linked with colorectal cancers are familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC).

3. Lifestyle


People ingesting diets rich in red and processed meats such as beef, lamb, hot dogs, etc. are at higher risk of colon cancer. At higher temperatures, if the meat is fried, grilled or boiled, this produces a certain chemical in them which increases the risk factor for colon cancer.

A diet rich in all the nutrients, salad, vegetables, high – fibres can reduce the risk of colon cancer and beautifies a person.

Inactive Lifestyle

The lifestyle of people nowadays has become really inactive, increasing the risk for colon cancers. People living a dormant lifestyle are at a higher risk

4. General


Age plays a vital role in causing colon cancer. Older age group people are more prone to it. Nearly 95 per cent of colon cancer or colorectal cancer occur in patients 45 or older than that. According to the National Cancer Institute, the median age of a patient diagnosed with colorectal cancer is 68.

History of Colon Cancer or Polyps

If you have already had colon cancer or colorectal cancer in the past, then there is a chance that cancer may redevelop in or around the same location of the original tumour. If your doctor finds a polyp during colonoscopy in your colon, then also you are at higher risk of colon cancer.


Being overweight is also one of the major causes of colon cancer.

How to Detect Colon Cancer Symptoms?

The following screening tests can be done for the detection of colon cancer symptoms:


A colonoscopy is a method that allows the doctor to look inside the entire colon and rectum. During a colonoscopy, a long, flexible tube (colonoscope) is inserted inside the rectum and colon. A tiny video camera allows the doctor to view all the clumps and polyps present inside the colon. During this procedure, the doctor may also remove some polyps or clumps. Removal of polyps reduces the risk of colon cancer.

It is also known as virtual colonoscopy. It is currently being studied in some laboratories. It used special X-Ray equipment to examine polyps. During the exam, a small tube is inserted a short distance into the rectum to allow for inflation with gas while CT images of the colon and the rectum are taken.

A sigmoidoscopy uses a flexible, lighted tube that is inserted into the rectum and lower colon to check for polyps, cancer, and other abnormalities. During this procedure, a doctor can remove polyps or other tissue for later examination. One of the drawbacks of sigmoidoscopy is that the doctor cannot check the colon's upper part, the ascending and transverse colon, with this test.

4. Stool DNA Tests

This test analyzes the DNA from a person's stool sample to look for cancer. It uses changes in the DNA that occur in polyps and cancers to find out if a colonoscopy should be done.
Colon Cancer Prevention

Some medications have been found to reduce the risk of precancerous polyps or colon cancer and some evidence links a reduced risk of polyps and colon cancer to regular use of aspirin or aspirin-like drugs. But it's not clear what dose and length of time are required to reduce colon cancer risk. Taking aspirin daily has some risks, including gastrointestinal bleeding and ulcers.

These options are generally reserved for people with a high risk of colon cancer. There is not enough evidence to recommend these medications to people who have an average risk of colon cancer.

If you have an increased risk of colon cancer or you develop any symptoms, discuss your risk factors with your doctor to determine whether preventive medications are safe for you.