Signs and Symptoms of Colon Cancer

Colon Cancer

Everything you should know about the colon cancer

Cancer is an uncontrolled multiplication of cells. It can develop anywhere. A localised tumour's cancer cells can invade other body parts (metastasis), causing further complications.

What is colorectal cancer?

The term colorectal cancer is used for cancer developing in the large bowel. The two parts of the large bowel, i.e., colon and rectum, can also have separate cancers, colon cancer and rectal cancer, respectively. If oyu would like to find out about other types of Cancer, you can view the Symptoms and Causes of Cancer here.

According to Cancer Research UK, bowel cancer is the 4th major cancer diagnosed in the United Kingdom, with over 41,000 annual cases and 16000+ annual deaths. Bowel cancer is also called colorectal cancer. It especially occurs at an advanced age, as 75% of deaths occur in people over 65. Therefore, you are more likely to develop colon cancer if you are older and have a number of diseases.

Several risk factors can predispose to colorectal cancer. The National Cancer Institute states that smoking can be directly related to colon cancer.

According to the Centre for Disease Control and Prevention, the most important risk factors for colon cancers are;

  • Diseases, e.g., Crohn's disease, inflammatory bowel disease, ulcerative colitis etc.

  • Genetic diseases, e.g., Lynch syndrome, familial adenomatous polyposis and family history.

  • Lifestyle factors, e.g., lack of physical activity, high fat and low fibre diet, smoking, alcoholism and obesity.

  • Advanced age

What would you experience with colon cancer? What are the most common colon cancer symptoms? Let's answer these questions.

What are the most common colorectal cancer symptoms?

Most bowel cancer symptoms are overlooked at the initial stages. However, as the tumour grows, the symptoms become more and more pronounced. In the final stage, a complete bowel obstruction can occur. The following symptoms of bowel cancer are often noted.

Weight loss, inappetence and weakness

Excessive weight loss in a short time should never be ignored.

The colon reabsorbs water from your excreta and makes it solid. Cancer in the colon will disturb water absorption, resulting in loose, watery stools. It will cause you to lose weight and become weak. The dehydration (due to diarrhoea), weight loss and anaemia will make you weak daily. Painful defecation will also negatively impact your appetite. All these factors will worsen the disease outcome.

A 2017 study found that a long-term weight loss of 5kg or more after the diagnosis of colorectal cancer was associated with poor overall survival.

Pain in the pelvic area

This pain is not very common if the cancer is restricted to the colon. However, if the tumour size grows rapidly, the pain can be felt in the whole of the pelvis.

The pain in the pelvic region also impacts life after successful treatment. For example, a study by Feddern and his colleagues in 2015 found that chronic pain after successful treatment of rectal cancer significantly reduced the quality of life, particularly of women.

Disturbed bowel habits

Defecation is a complex event and is controlled by the defecation reflex. However, you should not ignore if you observe the unusual and persistent changes in your bowel habit, e.g.,

  • Diarrhoea and constipation

  • Change in frequency and consistency of faeces

  • The stool shape is changed (thin or irregular shaped).

  • Change in bowel emptying

If you are observing these signs, first look for any dietary change. If no such change has occurred, visit your healthcare provider.


If the tumour has become too large and obstructs the flow of excreta and gas, you can feel nausea and vomiting. A failure to erect gas can also cause abdominal cramping and bloat. You can feel diarrhoea and scant faces with heavy straining. These symptoms are, however, experienced in a large number of problems. If you have a history of these signs for days, go for medical assistance.

Persistent pain in the abdomen

The abdominal pain in colorectal cancer is non-specific. You can feel tenesmus, i.e., a severe urge to defecate without any faeces. A blocked colon (due to a large tumour) can cause severe abdominal pain, which doesn't respond to any treatment. It can develop in both colon and rectal cancer. Seek medical assistance if you have no other cause of the problem and it is not responding to any treatments.

Blood in stools

If your stools are bloody, note if the blood is fresh or old. Bright red blood in the stools shows a problem in the rectum or colon. Fresh blood in the stools can also come from haemorrhoids or piles. But if the blood persistently comes into the rectum and worsens with time, it is likely due to colon cancer. Rectal bleeding should not be ignored and you should consult your doctor or GP immediately if you notice it. The blood due to haemorrhoids is not usually so persistent and changes continuously.

Signs of metastasis

Metastasis is the spread of cancerous cells to other organs or organ systems. Approximately 25% of colorectal cancer patients present with a severe metastatic problem. Heavy metastasis to the liver can produce pain in the right upper quadrant, while a heavy metastasis in the lungs can cause a disturbance of respiration.

An unknown fever which doesn't respond to any treatments also suggests metastasis. If cancer spreads to ovaries in females, disturbances in periods can also occur.


Anaemia is a deficiency of red blood cells, often associated with any bleeding disorder. For example, persistent intestinal bleeding can cause severe anaemia in colon cancer patients. Depending upon the severity of anaemia, you will note signs, e.g., paleness of skin, increased heart rate, weakness, fatigue, menstrual disturbances, etc.

According to a recent study published in the World Journal of Surgical Oncology, anaemia in colorectal cancer can be used to determine the expected outcome of the disease. The study found that only 21% of patients in stage 1 of cancer had anaemia. However, this percentage rose to 66% in the 4th stage. The anaemia was thus negatively related to the outcome of the disease.


The symptoms of cancer depend on the organ involved. The colon is a part of the large intestine, and so the symptoms of colon cancer are related to the digestive tract. It is important to know the pattern of these signs and see if any other problem is causing them. If these signs do not disappear and continue to worsen, immediately go for medical assistance, as it could be a sign of colon cancer.

If you are feeling the symptoms of bowel cancer, rush to your doctor. Don't worry; the treatment is possible in the early stages of cancer. Early diagnosis and healthy diet go a long way for beating bowel cancer. He will suggest you an appropriate treatment to kill cancer cells. Strictly cooperate with him to successfully beat bowel cancer.

Colon cancer screening services are offered particularly to senior citizens. Just dial 0800 707 60 60, and you will get a free screening service every two years if you are 60-74.

For a full range of medications, visit our Welzo Online Pharmacy.

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