Main Symptoms of Colon Cancer, Its Causes, and Treatments

Colon cancer usually originates from a small group of cells called an adenomatous polyp.

As time goes by, this benign group develops into what we know as colon cancer.

It is important to have an idea of ​​what exactly it is, its symptoms and other characteristics that allow it to be identified in time.

What is colon cancer?

It is a disease that develops because the mucosa of the colon that is in a polyp evolves to become a malignant tumor.

So colon cancer is an evolution of the mucosa in the polyp, and the malignant cells where they are lodged can usually be located between the intermediate and longest portion of the large intestine.

Worldwide, it is considered the most common type of cancer, and it is one of the easiest to diagnose.

On the other hand, if colon cancer can be detected early, it can be cured, cases of this disease have high cure rates.

Colon cancer takes a long time to develop.

It must be taken into account that the colon is, together with the rectum, the place where the feces are stored before being expelled to the outside through the anus.

Its role in our body makes it a place where waste substances accumulate, which is why it is so prone to cancer.

Due to this condition, it is recommended that the accumulation time be reduced, through a good diet that helps to avoid constipation.

What are the symptoms of colon cancer?

There are three main symptoms that allow detecting when there are problems in the colon that could point to cancer.

If these symptoms are identified and diagnosed early, a cure for colon cancer can be achieved in the patient.

Here are the symptoms:

1. Bleeding in the stool

It can be considered the most common symptom among those who suffer from colon cancer, when bleeding begins, the tumor has already formed.

You have to pay attention since the color of the blood could be red or black.

  • Red means that the tumor is present in the most distal part of the rectum and colon.
  • black means that it has been digested and therefore its origin is in the sections closest to the colon, black feces are called melena.

When this symptom is detected, you should see a doctor immediately, since if you do not receive the adequate treatment it could quickly worsen and suffer from anemia.

If anemia occurs, a product of the melena, symptoms such as the feeling of shortness of breath, dizziness, and tiredness will be added.

In addition to bleeding, a change in the size of the stool can be observed at this stage, which can also be narrower.

The reason for the above symptom is due to the narrowing of the intestine itself.

On the other hand, if the tumors are located in the distal part of the colon, it is likely that you will suffer from the feeling that when you have a bowel movement, you do not go completely.

2. Abdominal discomfort

This symptom is very common with colon cancer.

The reason for such discomfort is due to the obstruction made by the tumor in areas of the intestinal tube.

The discomfort can be very similar to colic. Complete intestinal obstruction can also occur, due to the intestinal tube being closed.

In these cases, medical attention is urgent to start a surgical process.

In the presence of these pains, it is time to proceed with a treatment that allows the cure of the disease.

3. Weight loss

Weight loss without an apparent cause is one of the common symptoms.

Ideally, follow-up should be done as soon as sudden, unexplained weight loss is detected.

In addition, appetite is also lost and constant tiredness develops in the person.

If stomach-related diseases are present, in addition to the symptoms mentioned, it is likely that colon cancer is advanced.

Colon Cancer Stages

The evolution of colon cancer can be divided into three fundamental stages:

  • local growth
  • lymphatic spread
  • Hematogenous spread

In each of these stages, the tumor deepens, below we present the table in each stage of evolution:

Evolution in the stage of local growth

Here the tumor has managed to invade the wall of the digestive tract completely.

It grows from the mucosa until it expands through the serosa and reaches the muscle layers.

The alarming thing is that if cancer passes beyond the wall of the intestine, it will spread to the surrounding organs.

lymphatic spread

This is the stage in which the tumor penetrates the wall of the intestine and reaches the organs, this is done through the network of lymphatic vessels.

The network of lymphatic vessels allows the malignant tumor to reach various lymph node regions.

The surprising thing is that the diffusion occurs in an orderly manner so that it reaches the nearby ganglia until it reaches those that are further away.

Hematogenous spread

At this stage of evolution, the tumor takes advantage of the bloodstream.

This is how it manages to spread cancer cells to the liver, lungs, bones, and to brain.


Colon cancer is unique in that it can be diagnosed early.

To achieve a diagnosis, the most reliable test is the stool blood test, with which it is determined whether or not there is blood in the stool.

If after the test the result is positive, a colonoscopy should be carried out, in this way the origin of the bleeding will be determined.

Colonoscopy can remove polyps so that tumor development can be prevented.

The advantage of the test is that it can be easily performed by the person presenting the symptoms. Only that the analysis must be done by a specialist.

It is important that this test is done every two years from the age of fifty.

The suspicion of a problem or injury in the colon should motivate the doctor to take a medical history and thus perform an examination and digital rectal examination.

The ways to establish a diagnosis of colon cancer are:

  • sigmoidoscopy
  • digital rectal examination
  • colonoscopy
  • Genetic study
  • Double-contrast barium enema

Why does colon cancer occur?

The reason colon cancer occurs is due to DNA changes inside the cells.

This is because DNA is the chemical that makes up genes, and also controls how cells work.

Therefore DNA affects much more than appearance.

When these changes occur as mutations that activate oncogenes or deactivate tumor suppressor genes, they result in uncontrolled cell growth and this translates into tumors.

Causes and risk factors of colon cancer

Risk factors are:

  • Advanced age: more than 50 years
  • Race: African-Americans have a higher risk of colon cancer
  • History: If you have previously suffered from the colon or adenomatous polyps
  • Intestinal diseases: chronic inflammatory diseases of the colon make you more prone to risk
  • Inherited syndromes: genetic syndromes transmitted, such as colorectal cancer or Lynch syndrome, among others.
  • Family history: if there is a family history you are more prone to risk
  • High-fat diet: high-fat and low-fiber is a combination that puts you at risk for colon cancer
  • Sedentary lifestyle: inactivity increases risk
  • Obesity
  • Diabetes
  • Harmful habits: smoking and excessive alcohol consumption increase the chances of colon cancer
  • Radiation therapy: If you have had cancer and have been treated with radiation therapy to the abdomen, this increases your risk of colon cancer.


Finally, we must make a series of recommendations so that you can avoid increasing the risks of colon cancer.

First of all, avoid excessive consumption of alcohol and tobacco.

Secondly, it is important that you have good control over your weight.

And thirdly, take care of your diet, it is best to go to a specialist so that they can indicate a balanced diet.

Follow these instructions and reduce the chances of colon cancer.