Bowel Cancer 101: Causes, Symptoms, Diagnosis & Treatment

Bowel cancer, also known as colorectal cancer, affects the wall of the large bowel. It is one of the most common types of cancer in Australia, so it’s essential to know the sign and symptoms of this disease. Find out more about Bowel Cancer, its causes, symptoms, diagnosis and treatments below.

What is Bowel Cancer?

Bowel cancer is an umbrella term to describe cancer affecting any part of the colon or rectum (large bowel). Depending on where cancer originates, it is sometimes called colon cancer, rectal cancer, or colorectal cancer. Collectively, bowel cancers are the third most common type of cancer in Australia, affecting around 15,500 people every year.

Most types of bowel cancer develop from a growth in the bowel’s inner lining which is called the mucosa. Often, it begins as small polyps (growths) on the bowel wall. Many people have polyps on their bowel walls which are benign (non-cancerous and harmless). However, some polyps can become cancerous over time. Polyps can be removed during a colonoscopy to prevent them from becoming cancerous.

Early detection is crucial for effectively treating bowel cancer. If untreated, cancer cells can grow deeper into the bowel wall and travel into the lymph nodes. Eventually, from there it has the potential to metastasise into other organs in the body. Bowel cancer can have very few symptoms, and some will have no symptoms at all, especially in cancer’s early stages. It is very important to undergo regular routine bowel screening if you are eligible and at risk of developing bowel cancer.

Your Bowel

Your bowel is part of your digestive system. It forms an important part of the gastrointestinal tract. The digestive system begins at the mouth and ends at the anus. It plays a crucial role in breaking down food for nutrients and energy and eliminating parts of the food that the body cannot use. Important parts of the bowel that can be affected by bowel cancer are the small bowel aka the small intestine, the large bowel or large intestine, and the anus.

The Small Bowel

This is longer but narrower than the large bowel. It is a 4-6 metre long tube that absorbs nutrients from the food you eat. It has three parts: the duodenum receives broken down food from the stomach, the jejunum or middle section of the small bowel, and the ileum. The ileum is the longest part of the small bowel and is responsible for transferring waste to the large bowel for elimination.

The Large Bowel

This is shorter than the small bowel, measuring about 1.5 metres in length. It is wider than the small bowel and is responsible for absorbing water and salts, turning what is left over from consumed food into faeces or stool for elimination. It has three main components: the caecum, a small pouch that receives waste matter from the small bowel, the colon, and the rectum.

The Anus 

This is the opening at the end of the bowel. The muscles of the anus relax when passing stool to remove waste. Cancer can also grow in the anus, however, anal cancer is separate from and treated differently from bowel cancer.

Types of Bowel Cancers

There are several types of bowel cancer, but the vast majority (9 out of 10 diagnoses) of bowel cancers are adenocarcinomas. Adenocarcinomas are a type of cancer that originates from the gland cells in your bowel’s lining. 

Other types of bowel cancer are less common and include:

1. Squamous cell cancers

Growths in the skin-like cell of the bowel lining

2. Neuroendocrine tumours

Affects the neuroendocrine cells in the bowel that create and release hormones

3. Small bowel cancer

Cancer growths in the small bowel or small intestine

4. Gastrointestinal stromal tumours

Growth of a special type of nerve cell, usually in the stomach or small intestine

5. Lymphomas

Cancers affecting the lymphatic system

Stages of Bowel Cancer

If you receive a diagnosis of bowel cancer, your doctor will also tell you how far the condition has progressed. This is called ‘staging’ and helps your physician understand how much cancer has grown and what type of treatment will be most suitable. The Australian system for classifying different stages of bowel cancer is called Australian Clinico-Pathological Staging (ACPS) system. It categorises bowel cancer into the following four stages.

4 Stages of Bowel Cancer

• Stage A – During this stage, the cancer is still confined to the wall of your bowel and has not spread.
• Stage B – During this stage, bowel cancer has spread to the outer surface of your bowel but has not travelled to the lymph nodes near the bowel.
• Stage C – During this stage, cancer is no longer confined to the bowel wall. In Stage C, cancer has been found in the lymph nodes near your bowel.
• Stage D – In the final stage, cancer has been found at distant sites from its origins in the bowel wall. It may have metastasised through the lymphatic systems into other organs such as the lungs or liver.

The longer you go without treatment, the more serious and difficult to manage your bowel cancer can become. If you are at risk of bowel cancer, it is crucial to undergo regular screening to help you and your doctor detect signs early. You should also be aware of and monitor for any early symptoms that you may have in bowel cancer.

Signs and Symptoms of Bowel Cancer

Detecting bowel cancer can be challenging because it can often develop without creating any specific symptoms. That is why it is so important to get regular screenings, such as a colonoscopy if you are at risk. However, many people do experience symptoms, especially as cancer progresses.

12 Signs and Symptoms of Bowel Cancer

1. Blood in Your Faeces (Poo)

This can show up in the toilet bowl or on the toilet paper.

2. Significant Changes to Your Bowel Movement Habits

This can include diarrhoea, constipation, or smaller, more frequent bowel movements.

3. Tenesmus

Feeling like you haven’t completely emptied your bowel after a bowel movement.

4. Bloating

Feeling a full or bloated sensation in your stomach, or a strange feeling in the rectum, especially during a bowel movement.

5. Thin Stools

Thin stools, visible mucus on the stool, or other changes in the appearance of your bowel movement.

6. Rectal or Anal Pain

Pain near the rectal or anal. This could occur around or inside your body.

7. Lumps

Developing a lump in the anus or rectum.

8. Tiredness

Unexplained tiredness or fatigue.

9. Weight Loss

Weight loss for no obvious reason.

10. Unexplained Anaemia

Low red blood cell count without any significant reason.

11. Stomach Pain

Stomach pain or cramping or bloating of the abdomen.

12. Blockages

One or more blockages in the bowel.

Having one or more of these symptoms is not a definitive sign that you have bowel cancer. Many of these symptoms are also common signs of other conditions such as anal fissures, haemorrhoids, diverticulitis, or inflammatory bowel disease. However, it is important to rule out bowel cancer and address any disease of gastrointestinal symptoms to prevent further complications. Always speak to your doctor about unexplained changes to your bowel movements, especially if you have one or more risk factors for developing bowel cancer.

Risk Factors of Bowel Cancer

There is no known cause of bowel cancer. Risk factors for bowel cancer are not clear in the available medical research, which is why screening is so important. However, from the available research, people with the following risk factors may be at a greater risk of developing bowel cancer.

12 Risk Factors of Bowel Cancer

1. Older Age

Bowel cancer is most common among people over 50 years old, with the risk increasing with age.

2. Genetic Factors

Some ethnic backgrounds appear to have a higher rate of bowel cancer diagnoses.

3. Existing Diagnosis of Inflammatory Bowel Diseases

Existing diagnosis of inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease. Your risk of developing bowel cancer may be even greater if you have had an inflammatory bowel disease for 8 years or longer.

4. Existing polyps in the bowel

Your risk may be greater if you have a large number of polyps in the bowel, or if you have previously had a specific type of bowel polyps known as adenomas.

5. Family History of Bowel Cancer

Strong family history of bowel cancer or bowel polyps.

6. Overweight or Obese

Being classified as overweight or obese.

7. LIfestyle Factors

Lifestyle factors such as; high fat, and low fibre diet. Diets high in processed and red meats, such as ham, salami and bacon, appear to be linked with an increased risk of developing bowel cancer.

8. Smoking

Smoking cigarettes or tobacco products.

9. Excessive Alcohol Consumption

Heavy or very regular consumption of alcohol.

10. Physical Inactivity

Sedentary lifestyle or inadequate physical activity.

11. Diabetes

Preexisting diabetes and/or insulin resistance.

12. History of receiving radiation therapy

History of receiving radiation therapy on the abdomen to treat previous cancers.

Causes of Bowel Cancer 

Bowel cancer is a complex disease, and doctors are not certain about what causes most types of bowel cancer. Generally speaking, cancer can grow in the bowel when normal, healthy cells undergo a mutation in their DNA. DNA is like a blueprint or instruction manual in every cell in your body. When a cell’s DNA becomes damaged, it can become cancerous and undergo uncontrolled growth. Over time, cell growth invades and damages other tissues in your body. This often begins with nearby tissues being affected first, but cancer can also travel (metastasise) and form deposits elsewhere in your body.

How is Bowel Cancer Diagnosed?

Finding bowel cancer in its earliest stages gives you the best chance to effectively manage your condition and make a complete recovery. That is why doctors recommend regular screening for certain people even if they are in good health and displaying no symptoms. Typically, adults should consider getting regular bowel screenings from about age 45, or earlier if they have one or more risk factors.

Several types of screening tests can help diagnose bowel cancer. They each have their benefits and drawbacks, so you should discuss your options with your doctor to find the most suitable diagnostic tools for you.

9 Common Screening Tests for Bowel Cancer

1. Physical and Rectal Examination

Physical examination is done by healthcare professionals to check patients’ general health. Rectal examination is also done by professionals, to check inside the rectum using their fingers. A rectal examination should be done in a short time, so it could be done with less or non-pain.

2. Blood Tests

There is no single blood test to diagnose bowel cancer, but blood tests can provide useful information about your health, such as the function of your liver and kidneys. Your doctor may also test for a chemical that can be produced by bowel cancer known as carcinoembryonic antigen (CEA). This chemical can be tracked over time to indicate your bowel cancer progress and/or how well you are responding to treatment.

3. Colonoscopy

Doctors use a long, flexible tube with a camera attached to view your entire bowel and look for signs of cancer.

4. Biopsy

If anything suspicious is found during a colonoscopy, your doctor may take a tissue sample through biopsy to test for signs of cancer.

5. PET-CT Scan

This is a combination of a Positron Emission Tomography (PET) scan and a Computed Tomography (CT) scan. It can be used to determine the progression and stage of your bowel cancer. 

6. MRI (magnetic resonance imaging) Scans

This can be used to take an image of your bowel and look for physical signs of damage.

7. Molecular Testing

This is sometimes used to check biopsy samples of advanced bowel cancers for gene mutations.

8. CT Colonography

This is also known as a virtual colonoscopy. It used CT technology to take an image of the inside of your bowel.

9. Flexible Sigmoidoscopy

Similar to a colonoscopy, a flexible sigmoidoscopy uses a long, thin tube to examine the rectum and lower colon.

Treatment of Bowel Cancer

Image Source: Bigstock

Your treatment journey will depend on the nature and staging of your bowel cancer. Every person’s experience of bowel cancer is unique, and your medical team will make recommendations based on your preferences, likelihood of treatment success, location and progression of the cancer, and your overall health status. Common treatment options for bowel cancer include surgery, chemotherapy and radiotherapy, systemic medication treatment and complementary therapies.

5 Treatment of Bowel Cancer

1. Surgery

Surgery is often the main type of bowel cancer treatment recommended. Surgical intervention will aim to remove the cancerous cells and any affected lymph nodes. Depending on the location and size of cancer, surgery may be keyhole or open. 

A common type of surgery is a colectomy in which part of your bowel, lymph nodes near the bowel and some normal bowel tissue surrounding the cancer are removed. Your surgeon will then reattach the two ends of the bowel, having removed the part affected by cancer. Depending on the site of the colectomy, it is called a colostomy (removing part of the large bowel) or an ileostomy (removing part of the small bowel).

2. Chemotherapy and Radiotherapy

Chemotherapy and/or radiotherapy are often used in conjunction with surgery. Radiotherapy can be used to reduce the size and number of cancer cells either before or after surgery. Chemotherapy is typically used to treat cancer that has spread from the bowel to the nearby lymph nodes or other organs. The use of these therapies will depend on your unique situation and should be explained in detail by your doctor.

3. Systemic Medication Intervention

Systemic treatment involves using drugs to target cancer cells throughout the body. Chemotherapy is considered one type of systemic treatment. Systemic treatment also includes targeted therapy, which involves using drugs to target specific molecules to block the growth of cancerous cells.

4. Complementary Therapies

If you want to explore complementary therapies, it is important to notify your doctor. These should always be considered as an addition to other treatments like surgery, medication, chemotherapy or radiotherapy. You should never cease your prescribed treatment without discussing it with your doctor. Complementary therapies vary widely and may offer you benefits such as a better mood, a sense of control and helping you to manage stress.

5. Side Effects of Bowel Cancer Treatment

Like all treatments, bowel cancer treatment can have side effects. Everyone will react to cancer treatment differently. You may experience temporary side effects or some that will be permanent. The side effects you experience will depend on your unique situation and should always be clearly explained by your doctor before undergoing treatment. If you are prescribed radiotherapy, it is important to note that this type of treatment performed on the pelvis area can impact your future fertility. Living with the impacts of cancer and cancer treatment can be an emotional, physical and mental challenge. The Cancer Council offer a support and advice service, staffed by caring cancer nurses. You can call them on 13 11 20 or email [email protected] to get information or support.

Support for People and Families Living With Cancer

If you or a loved one is living with cancer, there is no need to do it all alone. Help is available for you if you are struggling with your diagnosis or treatment, or if you are caring for someone with cancer. The Cancer Council Victoria can support you throughout your cancer journey and can be contacted on 13 11 20.

Carer support organisations can also be beneficial if someone you love is living with cancer. You can’t take care of someone else if you aren’t taking care of yourself, so don’t hesitate to reach out for help. Carers Australia are a great source of resources, information and support services for informal carers in Australia and can be contacted on 1800 242 636. Carer Gateway is Australia’s central source of support and information for carers and can link you with relevant local services or support groups. Find out more via their website or call them on 1800 422 737.

How Homage Can Help

Nursing Care from the Comfort of Your Home

Living with cancer is difficult enough without needlessly travelling back and forth from medical appointments. We understand that the time investment, cost and inconvenience of travelling to your doctor can make life more difficult, and we are here to help. Our Patient Transport & Medial Escort service provides you with a professionally trained, caring staff member to support you to get to and from important appointments, so you can focus on more important things.

Homage can also support you by providing high quality, professional nursing care from the comfort of your own home. Our compassionate and qualified Care Professionals are experienced in providing cancer care from the privacy and comfort of your own home. Spending more time in your home environment surrounded by loved ones can do wonders for your mental health whilst receiving cancer treatment. Reach out today to find out more about how we can support you and your loved ones through the complex journey of treatment and management.

Need some assistance with care for yourself or your loved one? Find out how Homage can help!