Overview – What is it?
Bowel cancer is a collective term for cancer that begins in the large bowel or intestine. However, depending on where it starts, it can also be referred to as colon or rectal cancer. The bowel is part of the digestive system which is made up of the small and large intestine, and the rectum. The small intestine is where the breakdown of food and absorption of nutrients into the body takes place, while the colon is where the absorption of water from undigested food takes place. The rectum is the last part of the colon and is where waste is stored until it is passed out of the body through the anus.
Some of the risk factors for bowel cancer are poor diet, being obese and having a family history with this type of cancer present.
It can cause symptoms such as abdominal pain, persistent change in bowel habits and presence of blood in the stool.
Bowel cancer can be diagnosed through digital rectal examination, colonoscopy and imaging tests, among other tests.
It can be treated through surgery, radiotherapy and biological treatments, among other treatment options.
Not smoking, limiting your alcohol intake and eating healthy are some of the things you can do to reduce your bowel cancer risk.
Causes – What causes it?
Some of the risk factors for this cancer are as follows:
- Digestive disorders such as Crohn’s disease or ulcerative colitis,
- Genetic conditions such as hereditary non-polyposis colorectal cancer,
- A poor diet high in red and processed meat,
- A Lack of physical activity,
- Overweightness and obesity,
- Smoking and excessive alcohol intake,
- Family history (if a close family member has bowel cancer that may increase your risk for this type of cancer), and
- Age (being 60 years and over).
Symptoms – What do you feel?
These are some of the common symptoms of bowel cancer:
- Presence of a lump in the abdomen,
- Having an unexplained and persistent change in bowel habit,
- Bleeding from the anus or in the stool,
- Discomfort, bloating and abdominal pain after eating,
- Unexplained weight loss, and
- Extreme fatigue.
Diagnosis – How do you diagnose it?
- Physical exam and medical history: During the initial consultation, the doctor will find out what symptoms you are experiencing and your medical history as well as that of your family, after which a digital rectal examination will be done to check for any abnormalities in your abdomen such as a lump.
- Imaging tests: These are used to check for any abnormalities in the bowel using computerised tomography (CT) or magnetic resonance imaging (MRI) to give detailed images of the bowel and rectum and surrounding organs, which can help in checking for any abnormalities such as the existence of a lump.
- Colonoscopy: This involves examining the entire bowel using a colonoscope (a device fitted with a camera and light). It is inserted into the rectum and moved along the length of the large bowel. This procedure is performed while the patient is under anaesthesia. As the colonoscope is being passed through the bowel, the doctor is able to see any abnormalities.
- Sigmoidoscopy: This procedure is similar to colonoscopy but uses a sigmoidoscope (a long, thin flexible tube attached to a small camera and light) to help check for abnormalities in the rectum and lower part of the bowel.
- CT Colonography: This procedure in used to check for polyps or cancers inside your large bowel. Gas is inflated into the colon to open it up and make any polyps that may be present, more visible.
Treatment – How do you treat it?
The treatment of bowel cancer depends on the stage of the cancer and its location in the bowel. Treatment options for this cancer include:
- Surgery: This is the main treatment for bowel cancer and is usually followed or combined with other treatments. It involves removing the cancer tumour or the affected part of the bowel or rectum. The different surgeries for bowel cancer are:
- Surgery for colon cancer which includes:
- Open colectomy done by making a large incision in the abdomen and removing a section of the colon,
- Robotic surgery done using a robot which is controlled by a surgeon to remove the cancer, and
- Laparoscopic (keyhole) colectomy performed by making a number of small incisions in the abdomen where a tiny camera and surgical instruments are inserted to remove a section of the colon.
- Surgery for rectal cancer which includes:
- Total mesenteric excision removing a large area of the rectum, the mesentery (fatty tissue around the bowel) and the border or rectal tissue that is not directly affected by the cancer,
- Local resection done to remove early stage rectal cancer and is aided by the use of an endoscope,
- Abdominoperineal used to treat cancer in the lower section of the rectum, and
- Anterior resection done to treat cancer that is not near the sphincter.
- Stoma surgery: This surgical procedure is carried out to remove a section of the bowel and join the remaining bowel. When the stoma is the made from large bowel or colon it is referred to as a colostomy, and if it is made from the small bowel it is referred to as an ileostomy.
- Chemotherapy: This is a treatment that uses anti-cancer medication to kill cancer cells.
- Radiotherapy: This involves using high-energy beams to destroy cancer cells.
- Target Therapy: It is a type of cancer treatment that uses drugs to target specific cancer cells without causing damage to normal cells.
- Biological therapy: This treatment involves using medicines that boost the body’s immune system, making it aware of cancer cells in the body, therefore, enabling it to fight the cancer.
Prevention – How do you prevent it?
As there is no specific way to prevent bowel cancer, reducing your risk factors is the best way to prevent yourself from developing this cancer. You can do so by:
- Eating a healthy diet, high in fibre and low in fats, and reducing your consumption of red meat and processed meat,
- Maintaining a healthy body weight,
- Doing regular exercises,
- Not smoking,
- Avoiding excessive alcohol intake,
- Getting regular screening, and
- Knowing your family history.