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Colorectal Cancer

April 20, 2022

Colorectal Cancer - featured image

The colon and rectum make up the large bowel which is the terminal parts of the gastro-intestinal tract. Colorectal cancer is a curable and preventable condition if detected early. These cancers usually begin in the inner lining of the large bowel as polyps. Polyps (benign abnormal growths) affect about 30% adults.

Risk Factors

The cause of colorectal cancer is unknown. Advancing age and certain factors can increase one’s risk for developing colorectal cancer. These include family history of colorectal cancer (especially parents or siblings), personal history of Crohn’s disease or ulcerative colitis, personal and family history of colorectal polyps, breast, uterine or ovarian cancer.


Colorectal cancer is preventable. Identification and removal of polyps through colonoscopy reduces the risk of colorectal cancer. Colorectal cancer screening recommendations are based on medical and family history. Screening typically starts at age 50 in patients with average risk. Those at higher risk are usually advised to receive their first screening at a younger age. 

Colorectal Cancer Symptoms

Colorectal cancer is often asymptomatic in the early stages and is detected during routine colonoscopy. Colorectal cancer symptoms can include: 

  • A change in bowel habits
  • Narrow/smaller shaped stools
  • Bright red or very dark blood in the stool
  • Ongoing abdominal or pelvic pain and bloating
  • Unexplained weight loss
  • Nausea or vomiting
  • Constant fatigue

Abdominal pain and weight loss are typically late symptoms, indicating possible advanced disease.

Diagnosis and Staging

  • Colonoscopy and biopsy: Examination of the entire colon with a long, thin flexible tube with a camera and a light on the end (colonoscope).
  • Computed Tomography (CT) scan: This test can accurately detect the presence of most cancer cells that have spread outside of the colon.

Surgical Treatment

Surgery to remove the colorectal cancer is almost always required for a complete cure. The tumour and lymph nodes are removed, along with a small portion of normal colon on either side of the tumour. A stoma is a surgically created opening that connects a part of the colon or small intestine to the skin of the abdominal wall. This procedure is typically only done in a very small number of colorectal cancer patients.
Minimally invasive surgical techniques such as laparoscopy or robotics may be used to remove the cancer. These techniques reduce hospital stay and allow for faster discharge and return to work. Typically, patients stay 4-5 days post op.

Chemotherapy may be offered either before or after surgery, depending on the stage of the cancer. Accurate staging can only be done once the complete cancer is removed and sent to the pathology lab for examination. Unlike rectal cancer, radiation therapy is not used for colon cancer.

Post-treatment Prognosis

Patient outcome is strongly associated with the staging. This is one reason why early detection through screening colonoscopy is crucial in order for cancers to be picked up early.

Follow-up with an oncologist after surgical treatment for colorectal cancer is crucial. Even when the cancer appears to have been completely removed or destroyed, the disease may recur. Undetected cancer cells can remain in the body after treatment. Your oncologist will monitor your recovery and check for cancer recurrence at specific intervals. Most patients will have a repeat colonoscopy one year after completion of treatment. Blood tests, clinical examinations and CT scans may be performed as per guidelines up to 5 years post op.

Who is a colon and rectal surgeon?

Colon and rectal surgeons are experts in the surgical and non-surgical treatment of diseases of the colon, rectum and anus. They have completed advanced surgical training in the treatment of these diseases as well as full general surgical training. Certified colon and rectal surgeons pass intensive examinations conducted by the Colleges of Medicine of South Africa. They are well-versed in the treatment of both benign and malignant diseases of the colon, rectum and anus and are able to perform routine screening examinations and surgically treat conditions if indicated to do so.

Dr Zaheer Moolla

(Sub-Specialist Colorectal Surgeon)

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