Colorectal screening is a procedure for maintaining colorectal health. It’s a preventative measure against colorectal cancer, the third most common cancer worldwide.
Despite its importance, many people feel apprehensive about the process due to a lack of understanding. In this article, we demystify colorectal screening, explain its importance, and detail the procedures involved.
What is a colorectal screening?
Colorectal screening refers to various tests and procedures to seek out early signs of conditions like:
- polyps
- colorectal cancer
- inflammatory bowel disease (IBD)
- dysplasia
- haemorrhoids
- diverticulitis and diverticulosis
These screenings are the key to early detection and prevention, potentially saving lives by identifying issues before they develop into more advanced stages. There are several types of colorectal screenings, broadly categorised into stool-based tests and visual exams.
Stool-Based Test
Stool-based tests analyse stool to identify potential signs of colorectal cancer. These noninvasive tests are convenient because they can be done at home and do not require any special preparation, such as dietary restrictions or bowel prep. There are three primary types of stool-based tests.
Highly Sensitive FIT
The Fecal Immunochemical Test (FIT) is a highly sensitive stool-based test that detects blood that is embedded within the stool, which can be an early sign of cancer. It uses antibodies to identify blood and is specific to human haemoglobin, yielding accurate results. The process involves:
- Collecting a small stool sample.
- Placing the sample in a container and returning it to the lab for analysis.
- Receiving results that indicate whether further diagnostic procedures, like a colonoscopy, are necessary.
Highly Sensitive gFOBT
The Guaiac-based Fecal Occult Blood Test (gFOBT) is another type of stool test that detects hidden blood. This test uses a chemical reaction to find traces of blood in the stool. Dietary and medication restrictions are required before the test to avoid false positives. The procedure involves:
- Collecting multiple stool samples on three different days.
- Smearing small amounts of stool on test cards.
- Sending the cards to a laboratory, where they are treated with a guaiac solution and analysed for colour changes indicating blood.
FIT-DNA
The FIT-DNA test, also known as a stool DNA test, combines FIT with a test that detects DNA mutations in stool. This test can identify abnormal DNA from cancerous or precancerous cells shed into the stool. It is more sensitive than FIT or gFOBT alone. The process includes:
- Collecting a stool sample using a kit provided by your healthcare provider.
- Sending the sample to a specialised lab.
- Analysing the sample for blood and DNA mutations.
- Receiving results that can indicate the need for further testing.
Visual exams of the colon and rectum
Visual exams enable doctors to directly observe the colon and rectum for abnormal growths or changes. These exams are more invasive, but they provide a real-time view and the opportunity to remove polyps during the procedure. Here are the primary visual exams used in colorectal screening.
Colonoscopy
A colonoscopy is considered the best test for colorectal screening. It involves using a colonoscope, a long and thin tube with a tiny camera to it, which enables the detection and removal of polyps or biopsy of suspicious areas. Here’s what to expect:
- Preparation: To empty the colon, a bowel prep, including laxatives and a clear liquid diet.
- Sedation: Administered to ensure comfort during the procedure.
- Procedure: The colonoscope is inserted from the rectum to view the entire colon.
- Post-Procedure: Recovery from sedation and possible minor side effects like bloating.
Virtual colonoscopy
Virtual colonoscopy, or CT colonography, uses CT scans to produce detailed images of the internal colon and rectum. It’s less invasive than a traditional colonoscopy and does not require sedation. The process includes:
- Preparation: Similar bowel prep as for a conventional colonoscopy.
- Procedure: Insertion of a small tube into the rectum to expand the colon with air for better imaging.
- Imaging: Detailed CT scans were taken to create a 3D colon image.
- Post-Procedure: Quick recovery, though a follow-up traditional colonoscopy might be required if abnormalities are found.
Sigmoidoscopy
A sigmoidoscopy is similar to a colonoscopy but inspects only the lower section of the colon and rectum. It’s less extensive and often done without sedation. The steps are:
- Preparation: Bowel prep focusing on the lower colon.
- Procedure: A flexible sigmoidoscope is inserted from the rectum to view the sigmoid colon.
- Post-Procedure: Minimal recovery time with potential for immediate results.
Who should get screened?
Screening is typically recommended for individuals starting at age 50, but those with a family history of colorectal cancer or certain genetic syndromes, might need to begin earlier.
Regular colorectal screenings can reduce the risk of colorectal cancer and contribute to long-term health.
Colorectal Screening in Singapore
Colorectal screenings can detect colorectal cancer, which often develops from precancerous polyps. These screenings can help you identify and remove polyps before they become cancerous. Early-stage colorectal cancer usually doesn’t present symptoms, making regular screenings vital for early intervention and increasing the chances of successful treatment.
At Ark Surgical Practice, we provide colorectal screening and treatment in Singapore. Our colorectal specialists are committed to helping you maintain optimal colorectal health and giving you the peace of mind you deserve.
