Bowel Cancer

Bowel cancer is one of the top three most common cancer in Hong Kong, with around 5000 new cases every year. Bowel cancer, if detected and treated early, is highly curable. Understanding the symptoms and causes of the disease enables early detection and treatment. Basic knowledge of the disease, treatment, necessary nursing and caring techniques enable speedy recovery and reduce the risk of relapse. Healthy diet, appropriate physical exercise and screening program could help to reduce risk of bowel cancer.

(Special thanks to Dr. Dominic CHAN, Consultant, Princess Margaret Hospital and Dr. Sunny WONG, Associate Consultant, Clinical Oncology, Princess Margaret Hospital for reviewing the information.)

The exact cause of bowel cancer is still unknown. People with the following characteristics are found to have higher chance to develop bowel cancer:
  • age over 50
  • with family history of bowel cancer
  • suffered from or had family history of chronic colitis or colon polyps
  • maintain a high-fat, high-cholesterol, low fiber diet 
  • overweight (body mass index over 25)
  • drink excessively
  • smoker
  • physically inactive
  • Smoker
  • physically inactive
Effective ways to prevent bowel cancer include:
  • adequate intake of dietary fiber: high fiber intake promotes bowel movement and reduces constipation, avoid intake of toxins and cancer-causing substances;
  • adequate intake of fruits and vegetables which are rich in vitamins and anti-cancer substances, high intake of which helps prevent cancer;
  • reduce consumption of red meat;
  • cooking with less oil; steam, bake, or grill instead of pan-fry or deep-fry;
  • exercise regularly and maintain a healthy weight;
  • quit smoking, drink less alcohol
  • participating in appropriate population-based screening programs such as fecal occult blood testing

Common signs and symptoms of bowel cancer include:

  • blood-stained stool, black stool, stools with mucus, or rectal bleeding;
  • change in bowel habits (constipation or diarrhea), change in shape of the stool (e.g. thin strip);
  • unexplained weight loss;
  • pain in the lower abdomen (distended abdomen or colicky abdominal pain);
  • persistent sensation of incomplete bowel movement;
  • physical symptoms of anemia: cold hands and feet, fatigue, rapid heartbeat, shortness of breath, pallor of skin, dizziness, and chest pain
High-risk individuals and people with the above-mentioned symptoms should consult family doctors and arrange for appropriate investigations as soon as possible. Bowel disease-related investigation include:
Colonoscopy is currently the best method to examine the lower digestive tract. By means of a flexible video-endoscope, the entire length of the colon as well as the terminal portion of the small bowel could be examined. The procedure generally lasts for 10 to 45 minutes.

Colonoscopy inspects the entire colon. Sigmoidoscopy is used to examine the sigmoid colon and rectum.
Colonoscopy is not only useful for diagnosis. With the use of different accessory equipment, biopsy can be performed and targeted procedures such as removal of polyp can be done.

Risks and Complications
Minor discomfort, including abdominal pain and distension is common. Major complications, including perforation, bleeding, heart and lung complications, infection or acute intestinal obstruction may occur. In general, the risk of major complication is less than 1%.  Patients should seek immediate help if they experience abdominal pain or discover blood in stools after the procedure.

Barium Enema Examination
Barium enema is a special x-ray procedure used to study the large intestine. Radiologist will introduce barium through a well-lubricated tube into the rectum. Liquid barium acts as a contrast to highlight specific areas in the body. The flow of the barium will be shown on an x-ray fluoroscopy screen to identify inner bowel wall abnormalities. 

Rectal Examination
Physician will insert a gloved and lubricated finger into the rectum through the anus and palpate the insides for any abnormal area or tumour.

Fecal Occult Blood Test
Bleeding in the bowel may not be physically apparent. This test checks for hidden blood in the stool.
If tumour is found, doctors may need to conduct computed tomography tests and other imaging studies. 


PhotoThe commonly used treatment modalities for bowel cancer include:
Surgical removal is the primary treatment for bowel cancer. It can cure both early stage bowel cancer and, in a minority of cases, those who have metastatic disease (e.g. to the liver or lung). The recent advances in minimally invasive surgery not only speeds up rehabilitation, but also greatly reduces the risk of complications, although it is not suitable for every single patient. For rectal cancer, total mesorectal resection is advocated to improve treatment result. Temporary or permanent stoma may be necessary in individual patients.

Adjuvant Therapy
Adjuvant therapy can reduce the chance of relapse in certain patients. Common adjuvant treatment that can be considered include radiation therapy and chemotherapy. Radiation therapy is the use of high-energy radiation to destroy cancer cells. It is mainly used in rectal cancer patients. Chemotherapy is the use of anti-cancer drugs to kill cancer cells. These treatments are usually given after radical surgery, although some patients require such treatment before surgery to facilitate surgical resection.
Who may need adjuvant therapy:
  • Stage II patients
    Adjuvant treatment may be considered for Stage II colon and rectal cancer patients with high-risk features.
  • Stage III patients
    Adjuvant treatment is generally recommended in Stage III colon and rectal patients.
  • Stage IV patients
    Adjuvant treatment is considered only if all the metastatic lesions and the primary tumour can be completely resected

Patients with hypertension, diabetes mellitus, coronary heart disease, and other chronic diseases should take extra care.

Patients in need of endoscopic therapy, such as polypectomy (removal of polyps), endoscopic hemostasis, as well as expansion and stent placement have higher risk of serious complications such as intestinal obstruction and bleeding.

Poor healing of surgical wound of the bowel may lead to peritonitis and sepsis. Inflammation and urinary dysfunction may also happen. However, it is worth noting that the more commonly used minimally surgery for bowel cancer has greatly reduced the risk of complications in recent years. 

Adjuvant therapy
Common side effects of radiotherapy and chemotherapy include: fatigue, vulnerable to infection or bleeding, loss of appetite, nausea and vomiting, hair loss, constipation or diarrhea.

Medication can reduce the severity of side effects.

There are a lot of things to take care of during the rehabilitation process. Better understanding will help patients to be more proactive and tackle their difficulties with a positive attitude.
Regular follow-up
Patients' condition, treatment and clinical presentations are different. Healthcare providers would discuss with the patient about their survivorship care plan, closely monitor patient's progress, and assess the patients' needs at survivorship follow-up.
Regular survivorship follow-up enables early detection of recurrence to facilitate timely treatment as well as minimizing complications. Getting treatment early improves patients' chance of cure.

Patients who have the rectum may have temporary or permanent stoma. Stoma Nurses will assist patients on how to choose the appropriate stoma appliances and educate the patient on proper stoma care.

Patients are suggested to avoid eating food items that are difficult to digest such as fatty food and those that may irritate the bowel e.g. curry or spicy food. Cancer treatment might weaken the immune system. Immunocompromised patient is advised to avoid consuming raw or undercooked meat, poultry, eggs, seafood, unpasteurized dairy products, and ready-to-eat raw vegetables.
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