Colorectal cancer

Topic - Colorectal cancer

A guide for patients and families

What is colorectal cancer Colorectal cancer starts in the colon or rectum, which make up the large bowel. Many cancers begin as small growths called polyps. Some polyps can turn into cancer over time. Removing them can help prevent cancer. Cancer found early is often easier to treat. Risk increases with age, but younger adults can develop it too. A family history, certain inherited conditions, previous polyps, or inflammatory bowel disease may mean you need earlier or different screening.

Symptoms to get checked

• Blood in your stool (poop) or bleeding from your bottom.
• A lasting change in bowel habits, such as diarrhoea, constipation, or feeling that your bowel does not empty fully.
• Ongoing abdominal cramps or pain, unexplained weight loss, or unusual tiredness. Slow blood loss may cause low iron or anaemia.

These symptoms often have other causes, but they need assessment. Do not assume bleeding is from haemorrhoids. Arrange an appointment promptly for persistent changes at any age; follow the urgent advice on the next page for bleeding or severe symptoms.

Screening and diagnosis Screening checks people who have no symptoms. A FIT (fecal immunochemical test) is a home stool test for hidden blood. A positive result does not prove cancer, but needs follow-up with a colonoscopy. Do not repeat FIT to try to cancel a positive result.

A colonoscopy uses a flexible camera to examine the bowel. Polyps can be removed and small samples (biopsies) taken to check for cancer. Blood tests and scans may then help assess your health and find the stage—how far cancer has spread.

Screening ages and intervals vary by province and personal risk. Ask your clinician when to start and which test is right for you. If you have symptoms, seek assessment even if your last FIT was normal. A normal screening result does not rule out cancer.

Treatment and support Treatment depends on whether cancer is in the colon or rectum, its stage, test results, your health and your wishes. Options include:

• Surgery to remove the cancer and nearby lymph nodes. Some very early cancers can be removed during colonoscopy.
• Chemotherapy medicines to kill cancer cells. Radiation is used mainly for rectal cancer, sometimes with chemotherapy before surgery.
• Targeted medicines or immunotherapy for selected cancers, guided by tumour tests. Ask whether these tests or genetic counselling are relevant to you.

Some people need a temporary or permanent stoma—an opening on the abdomen through which stool enters a bag. An ostomy nurse teaches you how to care for it. Palliative care can help relieve symptoms alongside cancer treatment.

When to seek help Call 911 now

• Heavy or nonstop rectal bleeding, especially with fainting, marked dizziness, cold clammy skin, or severe weakness.
• Collapse, severe breathing difficulty, or new severe chest pain.

Get emergency assessment now

• Severe abdominal pain or swelling with repeated vomiting, especially if you cannot pass stool or gas. This may be a bowel blockage. Do not try to treat it yourself with laxatives or extra fibre.

• During chemotherapy, a temperature of 38°C or higher: contact your cancer team immediately and follow their emergency plan. If you cannot reach them promptly, go to the emergency department. Do not wait until morning.

Get medical advice today

• New or unexplained rectal bleeding, black tar-like stool, or bloody diarrhoea. Seek emergency care if bleeding is heavy or you feel faint.
• Persistent vomiting or diarrhoea, inability to keep fluids down, very little urine, or worsening pain during treatment. Follow your team’s instructions for any stoma changes.

What you can do

• Keep appointments and ask how you will receive test results. After treatment, follow-up may include blood tests, scans and colonoscopy.
• Tell your team about changes in bowel habits, pain, appetite or weight. Ask for a dietitian if eating is difficult or you are losing weight.
• Drink enough to avoid dehydration unless your team has restricted fluids. After bowel surgery or with a stoma, follow your own food and fluid plan; high-fibre advice may not be suitable at first.
• Stay active within your ability. For long-term health, avoid smoking, limit alcohol and processed meat, and eat more whole grains, vegetables and fruit as tolerated.
• Check before using supplements or herbal remedies. Ask for help with anxiety, fatigue, body image, sexual health or practical needs. You do not have to manage these alone.

AI generated Canadian Cancer Society information and support: 1-888-939-3333. Sources and further reading Canadian Cancer Society • Colorectal cancer and care Screening for Life • FIT and colonoscopy in Alberta Canadian Cancer Society • Bowel obstruction NHS • Rectal bleeding (UK guidance; emergency number adapted for Canada)