Medical Director
Senior Consultant, General & Colorectal Surgeon
MBBS (Singapore), MRCS (Edinburgh), MMed (Surgery), FRCS (Edinburgh)
Finding out that something abnormal was identified during a colonoscopy can understandably raise questions about what it means for your health. However, an abnormal result does not necessarily mean that you have colorectal cancer. Colonoscopies can identify a range of findings, including polyps, inflammation and other changes in the lining of the colon.
What happens next depends on what was found, whether tissue or polyps were removed for laboratory examination and your individual health circumstances. Understanding the possible findings and next steps can help you know what to expect after an abnormal colonoscopy result.
How Are Abnormal Colonoscopy Findings Evaluated?
When an abnormal area is identified during a colonoscopy, the doctor will assess its appearance, size and location and determine whether it should be removed, sampled or investigated further. The approach will depend on the type of finding and what information is needed to understand it more clearly.
The Finding Is Assessed During the Colonoscopy
The doctor can examine the characteristics of an abnormal area while performing the colonoscopy. This initial assessment helps determine whether the finding can be addressed during the procedure or whether tissue needs to be collected for further examination.
Polyps May Be Removed for Analysis
Depending on their size, location and other features, some polyps may be removed during the colonoscopy. The removed tissue can then be examined in a laboratory to provide more information about the type of polyp and the changes present within it.
Abnormal Tissue May Be Biopsied and Examined
If an area of the bowel lining appears unusual, a small tissue sample may be taken for examination by a pathologist. Examining the cells and tissue under a microscope can provide information that cannot be determined from appearance alone and help establish a diagnosis.
What Can an Abnormal Colonoscopy Finding Mean?
The results of the colonoscopy and any tissue analysis can help determine what an abnormal finding represents. An abnormal result does not necessarily indicate cancer, as changes in the colon can have several possible causes. The diagnosis will depend on the type of abnormality identified and, where tissue was collected, what laboratory examination shows.
Colon Polyps
Colon polyps are growths that develop on the inner lining of the colon or rectum. Many colon polyps are non-cancerous, although certain types are considered precancerous because they have the potential to develop into colorectal cancer over time. Identifying the type of polyp can therefore help inform whether further monitoring is appropriate.
Inflammation or Ulceration
Inflammation or ulceration of the bowel lining can be associated with conditions such as inflammatory bowel disease, infections and other causes of bowel inflammation. The pattern of these changes, together with other clinical findings, can help doctors determine the possible underlying cause.
Diverticula and Other Structural Changes
A colonoscopy may reveal diverticula, which are small pouches that form in the wall of the colon, as well as other structural changes such as narrowing. Their significance will depend on the specific finding and whether it is associated with symptoms or other abnormalities.
Precancerous or Cancerous Changes
Some findings may show abnormal cellular changes that are precancerous, while others may be identified as cancerous. These results have different implications, so identifying the nature of the tissue is important before conclusions are made about colorectal cancer.
How Is Colorectal Cancer Confirmed After a Colonoscopy?
When tissue collected during a colonoscopy is examined, doctors look for changes that show whether cancer is present and what type it may be. The results can also provide information about how the cancer is behaving and, in some cases, whether it has grown into nearby tissue. This information helps doctors understand the diagnosis before deciding whether further tests are needed.
Cancer Cells Are Identified in the Tissue
Colorectal cancer is confirmed when examination of the tissue shows malignant cells. A pathologist assesses the cells under a microscope for changes that distinguish cancer from normal, benign or precancerous tissue. This allows a suspicious finding seen during the colonoscopy to be confirmed as cancerous.
The Type of Colorectal Cancer Is Identified
The appearance and arrangement of the cancer cells can provide more information about the type of tumour present. Most colorectal cancers are adenocarcinomas, which develop from gland-forming cells in the lining of the colon or rectum. Identifying the type of cancer helps establish the diagnosis more precisely and provides information relevant to subsequent assessment.
Further Tests May Be Needed to Determine Its Extent
Examination of removed tissue may sometimes provide information about whether cancer cells have grown into deeper tissue. However, samples obtained during a colonoscopy may not provide enough information to determine the full depth or extent of the cancer. Further investigations may therefore be required after the diagnosis is confirmed.
What Happens If Colorectal Cancer Is Confirmed?
If colorectal cancer is confirmed, further tests may be recommended to determine its stage. These can help assess how far the cancer has grown, whether it has spread beyond the colon or rectum and other factors relevant to treatment planning. The investigations needed will depend on the individual diagnosis.
Treatment will then be planned based on factors such as the cancer's location, stage and characteristics, as well as your overall health. Depending on these factors, treatment may involve surgery, systemic treatments or a combination of approaches. For some rectal cancers, radiotherapy may also be considered. Your healthcare team will discuss which options may be appropriate for your condition.
Get Clarity on Your Colonoscopy Results With Dr Chew Min Hoe
Understanding an abnormal colonoscopy result can give you a clearer picture of what it means for your health and what comes next. Your colonoscopy findings, together with any biopsy or polyp analysis, can help clarify the abnormality and guide any further tests, treatment or follow-up. This can help you have a more informed discussion with your doctor about your ongoing colorectal care.
At our colonoscopy clinic in Singapore, we support patients through colonoscopy assessment, diagnosis and ongoing colorectal care. Senior Consultant, General & Colorectal Surgeon Dr Chew Min Hoe provides recommendations based on each patient's colonoscopy and pathology findings, overall health and follow-up needs. If you have received an abnormal colonoscopy result, book an appointment to discuss what your findings may mean and the appropriate next steps.
Related Media Features
Read more from Dr Chew Min Hoe through his media features and contributions:
- How Accurate Is Colonoscopy for Detecting Colon Conditions?
- When Should You Consider a Colonoscopy?
- Colorectal Cancer: A Guide to Diagnosis and Early Detection
FAQs About Abnormal Colonoscopy Results
How long does it take to receive results after an abnormal colonoscopy?
+
If tissue or polyps are sent for laboratory analysis, the final results may not be available immediately after your colonoscopy. The time required can vary depending on the tests performed and the healthcare facility. Your doctor can advise when your results are expected and arrange a follow-up to discuss them.
Can a colonoscopy miss an abnormality?
+
A colonoscopy allows the doctor to examine the lining of the colon directly, but no test can detect every abnormality. Detection can be affected by factors such as the quality of bowel preparation, the location or appearance of an abnormality and whether the entire colon could be examined. In some cases, further investigation may be recommended.
What if my colonoscopy was abnormal but my biopsy was benign?
+
A benign biopsy means cancer was not identified in the tissue examined. Whether you need further assessment or follow-up will depend on what was seen during the colonoscopy, the area that was sampled and whether the biopsy findings adequately explain the abnormality.
Can I have an abnormal colonoscopy result without having symptoms?
+
Yes. Some colorectal abnormalities may not cause noticeable symptoms, particularly in their earlier stages. This is one reason polyps and other changes may be discovered during screening before they cause problems.
Does the size or number of polyps affect what happens next?
+
It can. The number, size and type of polyps identified can influence whether and when another colonoscopy is recommended. Your doctor will consider these characteristics alongside the laboratory findings and your individual risk factors when advising on future surveillance.
Meet Our Colonoscopy Specialist in Singapore
Medical Director
Senior Consultant, General & Colorectal Surgeon
MBBS (Singapore), MRCS (Edinburgh), MMed (Surgery), FRCS (Edinburgh)
Dr Chew Min Hoe has devoted over 25 years of service to the public sector and was the founding Head of the Department of Surgery at Sengkang General Hospital (SKH). His clinical speciality is General and Colorectal Surgery with special niche interests in colorectal cancer, advanced pelvic tumours, hereditary conditions as well as perianal surgery. He is highly involved in education and research and has published more than 100 peer-reviewed articles.
