Bowel Cancer Symptoms: What You Need to Know for Early Detection

Bowel cancer is cancer that occurs in any part of the large bowel, which includes the colon and rectum. It is the second highest cause of cancer deaths in New Zealand with more than 1,200 people dying from bowel cancer each year. It often has no symptoms or very few symptoms in the early stages, making it important to understand the signs and if you should start screening/testing for it. If bowel cancer is caught early, 90% of bowel cancer cases can be treated successfully.

What is bowel cancer?

Bowel cancer also known as colorectal cancer occurs in any part of the large bowel. Depending on where it starts it may also be called cancer of the colon, or cancer of the rectum. The majority (about 9 out of 10) of bowel cancers are adenocarcinomas, which start in the gland lining of the bowel.

Doctors use staging to indicate how far cancer has spread the size of any tumours. Your symptoms will often depend on the stage of the cancer.

Stage 1: Cancer is confined to the inner lining of the bowel.

Stage 2: the cancer has spread to the outer surfaces of the bowel wall.

Stage 3: Cancer has spread to the lymph nodes near the bowel.

Stage 4: Cancer has spread to other parts of the body (e.g., liver or lungs).

What are the symptoms of bowel cancer?

In it’s early-stages bowel cancer may have no symptoms or very few symptoms. Symptoms at the early stages may include:

Blood in the stool.
Change in frequency of bowel movements.
Change in type of bowel movement (e.g., diarrhoea, constipation, narrow stools).
Abdominal pain or cramping.
Bleeding from rectum.
Anaemia, due to intestinal bleeding.
Unexplained tiredness.

As bowel cancer progresses you are more likely to experience the symptoms listed above. Additionally, some late-stage symptoms you may experience in include:

Unexplained weight loss.
Fatigue and weakness.
Persistent changes in your stool (beyond one month).
Swelling in the hands or feet.
Breathing difficulties.
A lump or mass in the abdomen.
Yellowing of the eyes and skin (jaundice).

If you have any of the symptoms listed above (early-stage and late-stage), or you are concerned about bowel cancer, see your GP or a healthcare professional right away.

What are the risk factors of bowel cancer?

There are a range of risk factors that increase your risk of bowel cancer. Some of these include:

Age increases your risk; most cases are found in people over 50 years old. *
If you have had polyps in the bowel.
Having a family history of bowel cancer or polyps in the bowel.
Having Crohn’s disease or ulcerative colitis (inflammatory bowel diseases).
Having an inherited genetic condition such as hereditary non-polyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP).

*While bowel cancer is more common in those older than 50 years, it affects people of all ages. Over 350 people under 50 are diagnosed with bowel cancer each year in New Zealand.

Lifestyle risk factors that should be avoided include:

Smoking tobacco.
Being overweight or obese.
Drinking alcohol.
Consuming a diet high in processed meats and/or fats.
Having type 2 diabetes.
Being sedentary or not exercising often.

How is bowel cancer diagnosed?

If you have any of the symptoms of bowel cancer (early-stage and late-stage), or you are concerned about bowel cancer, your GP can make an accurate diagnosis.

Bowel cancer can be identified after a screening test. If you have symptoms, your healthcare provider will usually recommend a colonoscopy to check for bowel cancer.

If bowel cancer is diagnosed, additional tests may be done to determine what stage the disease is in.

As bowel cancer can be difficult to self-identify, especially in its early stages, it is often caught during routine screening. This routine testing is done with hopes to catch the disease early.

The National Bowel Screening Programme is open to New Zealanders eligible for publicly funded health care, depending on their age. It is a free government-run programme offered every two years to people aged 60 to 74. In some areas Māori and Pasifika are invited to participate in bowel screening from 50 years old.

Further Information

Bowel Cancer New Zealand