<img height="1" width="1" src="https://www.facebook.com/tr?id=914352225269004&amp;ev=PageView%20&amp;noscript=1">


Understanding colorectal polyps: Causes, symptoms & how clinical research can help


Olivia Ustariz

Date Published

24 August 2023


Colorectal polyps, otherwise known as bowel polyps, are abnormal growths that form on the inner lining of the colon or rectum. According to the Sydney Gastrointestinal Specialists, roughly half of all Australian adults develop a colorectal polyp during their lifetime. 

And though most colorectal polyps are harmless and do not cause any symptoms or health issues, some can develop into bowel cancer over time if not detected and removed. As such, it is crucial to understand their causes, symptoms, and how clinical research can help us better identify and address colorectal polyps. 

In this blog post, we will delve into the world of colorectal polyps and shed light on their origin, potential warning signs, and diagnostic and treatment options. We will also explore how clinical research can be instrumental in unravelling the mysteries of colorectal polyps and improve how we find and diagnose colorectal polyps and bowel cancer. 

What are colorectal polyps?  

As we mentioned earlier, colorectal polyps are abnormal growths that form on the inner lining of the colon or rectum. They are typically harmless and cause no symptoms, and so are often discovered incidentally during colonoscopies and other routine screenings. 

However, they are similar to cancer in that they are caused by abnormal cell growth and rapid cell division. As such, they can become malignant and develop into bowel cancer over time if not detected and removed. 

Colorectal polyps can be broadly categorised into two main categories: nonneoplastic and neoplastic. Neoplastic polyps, which include adenomas and serrated types, are the most likely to turn into cancer if allowed to grow unchecked. However, doctors typically recommend treating all colorectal polyps among detection to prevent any potential cancer from developing. 

What are the causes of colorectal polyps? 

While the exact cause of colorectal polyps is not known, several risk factors can contribute to their development: 

  • Age: Colorectal polyps are more common in individuals aged 50 and above, with the risk increasing as one gets older. 
  • Family History and Genetics: A family history of colorectal polyps or bowel cancer can increase a person's risk of developing polyps. Certain genetic conditions, such as familial adenomatous polyposis (FAP) and Lynch syndrome (hereditary nonpolyposis colorectal cancer or HNPCC), can also predispose a person to the formation of polyps.
  • Dietary Factors: A diet low in fibre, fruits, and vegetables and high in red and processed meats, as well as excessive alcohol consumption, have been associated with an increased risk of colorectal polyps. 
  • Inflammatory Bowel Disease (IBD): Conditions such as ulcerative colitis and Crohn's disease, collectively known as inflammatory bowel disease, can elevate the risk of developing polyps over time.
  • Lifestyle Choices: A sedentary lifestyle and obesity have been linked to a higher likelihood of colorectal polyps.
  • Smoking: Smoking tobacco is considered a risk factor for colorectal polyps and cancer.
  • Personal History: A person who has previously had colorectal polyps is at a higher risk of developing new polyps in the future.

It is crucial to note, having one or more of these risk factors does not guarantee you will develop polyps, nor does their absence guarantee immunity. 



What are the symptoms of colorectal polyps? 

Colorectal polyps often manifest discreetly with no noticeable symptoms. However, some polyps may give rise to subtle warning signs, particularly when they grow large or become precancerous:

  • Rectal Bleeding: One of the most common signs is rectal bleeding, which may appear as bright red blood in the stool, toilet bowl, or on toilet paper. 
  • Changes in Bowel Habits: Persistent alterations in bowel habits, such as sudden changes in stool consistency (e.g., diarrhoea or constipation), or a feeling of incomplete bowel movements, might be linked to the presence of polyps.
  • Abdominal Pain or Cramps: Some people may experience abdominal discomfort, cramps, or persistent pain, particularly if the polyps are large or located in specific areas of the bowel. 
  • Unexplained Anaemia: Colorectal polyps that bleed slowly over time can lead to iron deficiency anaemia, the symptoms of which include fatigue, weakness, and pallor, without an apparent cause.
Colorectal polyps: Diagnosis & treatment

Colorectal polyps can be detected through various screening methods, including:

  • Colonoscopy: This is the most reliable and widely used screening method. A colonoscope, a flexible tube with a camera, is inserted into the colon and rectum to visualise the intestinal lining and any polyps. During the procedure, the doctor can also remove polyps for further examination or as a preventive measure.
  • Flexible Sigmoidoscopy: Similar to colonoscopy, this procedure uses a sigmoidoscope to examine the lower part of the colon. However, it may not detect polyps higher up in the colon.
  • Virtual Colonoscopy (CT Colonography): A non-invasive imaging test that uses a CT scan to create detailed 3D images of the colon, which allows any polyps to be detected without a traditional colonoscopy. If polyps are found, however, a subsequent colonoscopy may be required for removal.
  • Stool Tests: Stool-based tests, such as the National Bowel Cancer Screening Program, are used to detect blood in the stool, which could indicate the presence of polyps or bowel cancer.

Once polyps are detected and removed, they are formally diagnosed through examination under a microscope, otherwise known as a histological examination. This type of examination helps identify the type of polyp, determine whether it is precancerous or benign, and guides further management and surveillance. 

The treatment of colorectal polyps, much like their diagnosis, revolves around their early detection and removal. The two main methods of polyp removal are: 

  • Polypectomy: This procedure involves removing small polyps, typically less than 1 centimetre in size, during a colonoscopy. Using a wire loop called a snare, the doctor excises the polyp from the intestinal lining.
  • Endoscopic Mucosal Resection (EMR): For larger or sessile (flat shaped) polyps, an EMR may be necessary. During this technique, the polyp and its surrounding tissue are lifted before removal, which allows for better evaluation and ensures complete excision.

After removal and examination, your doctor may recommend follow-up colonoscopies to monitor for new polyp growths, depending on your risk factors. 

Colorectal polyps: How clinical research can help

Enter clinical trials, which help improve diagnostic methods by evaluating new approaches, technologies, or markers, and their effectiveness in guiding clinicians towards more precise and early diagnoses. We are currently recruiting for a new research study aiming to identify biological markers in blood or stool that will improve how colorectal polyps and bowel cancer are found and diagnosed. 

By joining this trial, you could be at the forefront of cutting-edge research, contribute to medical breakthroughs, and help pave the way towards a bright and healthier tomorrow. Head to our website to learn more about the trial and see if you are eligible to participate. 

Final thoughts  

Though often benign, colorectal polyps can develop into bowel cancer if left untreated. By understanding their nature, symptoms, and risk factors, you can take proactive steps to safeguard your well-being. To this end, early detection and removal of polyps through regular screenings are vital for ensuring better health outcomes. Clinical trials are advancing the way colorectal polyps and bowel cancer are detected. By participating in clinical trials, like the one for which we are currently recruiting, you can make a lasting impact in the world of medical research and help shape a healthier future for generations to come. 

To find out more about this study, and other studies for which we are currently recruiting, head to the Active Trials page on our website.