Bowel Cancer

Bowel cancer is the generic term for a cancer developing in the large bowel, which consists of the colon and rectum. Bowel cancer can therefore be further classified as colon cancer or rectal cancer.

Function of the large bowel

The body’s digestive system consists of the oesophagus, stomach, duodenum, small bowel and large bowel. The first six feet of the large bowel is known as the colon and the last six inches is the rectum, which connects to the anal canal. The main function of the colon is to absorb water from bowel contents to form a solid motion/stool. The rectum acts as a storage reservoir for formed stools to be expelled as a bowel motion.

Cancer develops when the cells lining the inside surface of the bowel turn cancerous (also known as malignant cells). Cancer arising from the colon or the rectum is also known as bowel cancer or colorectal cancer.

What causes bowel cancer?

Bowel cancer often develops from a pre-cancerous growth, known as a polyp. Polyps are usually non-cancerous but if untreated, some can develop into cancer by growing in size and penetrating into the bowel wall. The exact causes of bowel cancer are not known, however some risk factors have been recognised to increase the risk of developing this disease:

  • Increasing age (majority of cases are over 50 years)
  • A diet high in fat, red or processed meat and low in fruit and vegetables
  • An inactive lifestyle and being overweight
    Family history of bowel, breast or ovarian cancers consisting of a first degree relative (such as parent, sibling or child who has developed polyps, colon or rectal cancer). If this is the case regular bowel cancer screening should be discussed and considered. Family history screening is the most effective is offered by the Birmingham Bowel Clinic.
  • A previous diagnosis of ovarian cancer or breast cancer or polyps in the colon or rectum
  • A previous diagnosis of Inflammatory Bowel Disease such as Ulcerative Colitis or Crohn’s disease .


Symptoms of Bowel Cancer

As with most forms of cancer, early detection is associated with the best chances of cure and survival. Some of the symptoms of bowel cancer include:

  • Change in bowel habit including diarrhoea and constipation
  • Blood in the stools - bleeding can be very dark or bright red in colour
  • An incomplete feeling of emptying after having a bowel movement
  • Abdominal pain and discomfort, including feeling bloated
  • Loss of appetite
  • Fatigue and breathlessness which may be due to anaemia
  • Unexplained weight loss

Unfortunately many bowel cancers do not cause any symptoms until they are very advanced, highlighting the importance of screening.


How bowel cancer is investigated?

Symptoms of bowel cancer should be investigated through a combination of the following:

  • Clinical examination of abdomen (tummy) and back passage
  • Flexible sigmoidoscopy procedure which will allow the consultant to examine the rectum and the lower part of the colon
  • Colonoscopy investigation will allow the consultant to examine the entire large bowel including all of the colon and the rectum
  • CT scan which may include CT colonography (also known as a virtual colonoscopy)

If an abnormality is found on examining the bowel, a biopsy is usually taken to make the diagnosis of bowel cancer. The biopsy will be examined by a histopathologist.

If the diagnosis of cancer is confirmed, further investigations are required to assess the size and extent (stage) of the cancer.

These will usually include a CT scan, and in cases of rectal cancer an MRI scan as well. Sometimes other investigations, including a PET scan and endoscopic ultrasound are needed.


Bowel Cancer Treatment

After a diagnosis of bowel cancer has been made, scans are carried out to determine how far the cancer has spread within the bowel and if it has spread to other parts of the body, such as the liver and the lungs. At this point the specialists including the surgeons, radiologist, histopathologist and oncologist will meet as a team and review the case and results of the investigations to decide on the most appropriate management of the cancer.

The most appropriate treatment for bowel cancer is dependent on the TNM (tumour, node, metastasis) stage of the cancer:

  1. How deep is the cancer within the bowel and whether it has spread to the surrounding tissues?
  2. Has the cancer spread to the lymph nodes?
  3. Has the cancer has spread to other parts of the body such as the lungs and liver?

The main treatment for bowel cancer is surgery, which usually involves removal of the affected part of the bowel and the surrounding lymph nodes. However, surgery alone is not always successful in curing bowel cancer and often chemotherapy or radiotherapy is given before or after surgery, either to shrink the cancer prior to removal or to reduce the risk of the cancer returning later on.

If the cancer is diagnosed in its early stages as a very small lump, surgical excision alone can also be an effective treatment.

Some of the specialised surgery offered at the Birmingham Bowel Clinic to treat bowel cancer can include the following proecdures:

For more details visit Cancerhelp, part of Cancer Research UK.


What our Patients think :

What are the next steps?

If you think you have this condition or any of these symptoms you will need to seek medical advice.

For more information or to make an appointment: