What is Bowel Cancer? Causes, Symptoms and Treatment

Bowel cancer is a general term that is used to describe cancer that begins in the large bowel. Depending on where in the bowel the cancer starts, bowel cancer can sometimes be referred to as colon cancer, or rectal cancer.

For various reasons, a significant increase in the incidence of colon cancer has been noted in the last decade.

Approximately 80 per cent of bowel cancer cases develop in people aged 60 years and above. Two thirds of bowel cancers develop in the colon, with the remaining third developing in the rectum.

Many patients visit the doctor for the first time when their cancer is already at a very advanced stage and has spread to the liver and other organ. Unfortunately, such patients die within a year, despite the best possible treatment.

What is Bowel Cancer

Risk Factors for Bowel Cancer:

  • Eating a high-fat diet
  • Bowel conditions like crown’s disease and ulcerative colitis
  • A family history of bowel cancer
  • Alcohol misuse
  • Excess smoking
  • Obesity

Initial Symptoms:

• Blood in stools and/or bleeding from rectum.
• A change in normal bowel habits that persist for more than six weeks, such as diarrhea, constipation, or passing stools more frequently than usual.
• Persistent abdominal pain.
• Unexplained weight loss.
• In some cases, it can also cause an obstruction in the bowel.

Origin and Spread:

• Most cases of bowel cancer first develop as clumps of cells on the inner lining of the bowel. These clumps are known as polyps. (But development of polyps does not necessarily mean that you will get bowel cancer.)

• Bowel cancer can spread through the walls of the bowel into nearby lymph nodes.


A doctor will carry out a physical examination known as digital rectal examination, it involves the doctor gently placing his finger into the anus, and then up into the rectum, trying to feel any lump. In further examination, the tests that are used to confirm diagnosis of bowel cancer are:

• Colonoscopy – the examination of the entire large bowel.
• Barium enema – a type of X-ray to study the bowel in more detail.

Further testing will be done if the diagnosis of bowel Cancer is confirmed. It is usually carried out for two reasons: To check if the cancer has spread from the bowel to other parts of the body and to help decide what will be the most effective treatment. The tests may include:

• CT scan and MRI scan – to provide a detailed image of the colon.
• Ultrasound scans – to look inside other organs, such as liver, to see if the cancer has spread there.
• Chest X-rays – to assess the stat of the heart and lungs.
• Blood test – the cancerous cells release a special protein, known as tumor marker, which can be detected through a blood test.

Screening for Bowel Cancer:

• Screening is done by testing the stool sample for the presence of blood. All patients with positive stool samples for occult blood should undergo endoscopic examination of the colon.

• All healthy persons aged above 60 years and having any of the risk factors mentioned must undergo colonoscopy screening

• Screening is important; the earlier the diagnosis, the greater is the chance of complete cure. Bowel cancer that is diagnosed in its earliest stages has a fair rate of patient survival and complete cure is usually possible.

Staging and grading after diagnosis:

At the completion of these examinations and tests, it should be possible to determine what stage and grade the cancer is. Staging refers to how far the cancer has advanced, and grading relates to how aggressive the cancer is and how likely is it to spread.

Bowel Cancer Treatment and Management:

A multi-disciplinary team comprising a number of specialists is necessary to treat bowel cancer. They include gastroenterologist-physician cum surgeon (a specialist in bowel surgery), clinical oncologist and specialist in the non-surgical treatment of cancer.

The recommended treatment plan will depend on the stage and location of the bowel cancer.

• If the cancer is confined to the rectum, radiotherapy will be used to shrink the tumor, and then surgery may be used to remove the tumor. Sometimes, radiotherapy is combined with chemotherapy, which is known as chemo radiation.

If it is a very early stage bowel cancer, it should be possible to surgically remove the cancer with no requirement for any further treatment. But this is uncommon because most patients are diagnosed very late.

Radiotherapy in Two Ways:

• It is given before surgery, in cases of rectal cancer.
• It is used to control symptoms and slow the spread of cancer, in cases of advanced bowel cancer (where it is also referred to as palliative radiotherapy).
• Radiotherapy given before surgery for rectal cancer can be performed in two way:
• External radiotherapy – a machine is used to beam high energy waves at the rectum in order to kill cancerous cells.
• Internal (known as brachytherapy) – a radioactive tube is inserted into the anus and placed next to the tumor to shrink it.

Surgery (Colectomy)

If the cancer is at a very early stage, it may be possible to remove just a small piece of the lining of the colon wall. This is known as local excision.

If the cancer has begun to spread into the muscles surrounding the colon, it will usually be necessary to remove and entire section of the colon.

Removing some of the colon is known as a hemi-colectomy. Depending on the location of the cancer, possible surgical procedures are undertaken.

• Open colectomy – where the surgeon makes a large incision in your abdomen and removes a section of your colon.
• Laparoscopic colecotmy – a type of ‘keyhole’ surgery to remove a section of the colon..


It is done in 3 ways. It can last up to 6 months.

• Before surgery for rectal cancer in combination with radiotherapy,
• After surgery to prevent the return of cancer.
• To slow the spread of advance bowel cancer and to help control the symptoms.

Chemotherapy comes with all its known side effects. To mention are fatigue, nausea, vomiting , diarrhea, mouth ulcers, hair loss, redness and soreness on the palms of hands and sloes of feet, sensation of numbness, tingling and/or burning in hands, feet, and neck.

These side effects should gradually pass when treatment is finished. It usually takes between three and six months for your hair to grow back.

Follow up Treatment:

Almost all survivors of colon cancer require some kind of follow up treatment through the rest of their lives. It is because of the definite possibility of recurrence.

Repeated colonoscopy is the single best investigation to detect the recurrence of colon cancer. A recurrent colon cancer too can be treated successfully, if detected early.

SOURCE: B-Positive Health Magazine

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