Flexible Sigmoidoscopy – What You Need to Know
If you’re experiencing problems in your rectum or colon, a flexible sigmoidoscopy is a safe, effective, and relatively painless way to get some answers. Used to investigate symptoms such as rectal bleeding, unexplained digestive issues, and long-term bowel problems, it is instrumental in diagnosing polyps and other irregularities. While it does not replace a full colonoscopy, it offers an endoscopic examination of the sigmoid colon and rectum.
What is a Flexible Sigmoidoscopy?
A flexible sigmoidoscopy is a procedure in which a doctor examines the lower part of the large intestine (also known as the colon or large bowel) using a flexible, narrow tube with a light and a tiny camera on the end, called a sigmoidoscope. The test involves a long, thin, flexible tube (the sigmoidoscope) equipped with a light and a small camera, enabling simultaneous imaging and possible tissue sampling (biopsy).
Symptoms such as chronic diarrhoea, constipation, abdominal pain, rectal bleeding, or suspected polyps should be screened as a rule. Doctors can use this direct examination of the colon lining to detect early signs of conditions such as colorectal cancer and inflammatory bowel disease.
Flexible Sigmoidoscopy vs. Colonoscopy: Key Differences
Both tests are used to look for problems in the colon, but one is more specific than the other. A colonoscopy examines the entire colon (large intestine), while a flexible sigmoidoscopy focuses only on the lower part—the sigmoid colon and rectum.
This difference in coverage means a colonoscopy is more extensive, particularly for patients with symptoms suggesting colon disease or those at high risk of colon cancer. However, a flexible sigmoidoscopy is quicker, typically lasting 10 to 20 minutes, and is usually performed without sedation.
Preparation for a sigmoidoscopy is also simpler. The lower colon is generally not as difficult to clean as some assume—unlike a full bowel cleanse, you may only need a mild laxative or even just an enema to clear the lower colon. Sedation is rarely required, and most patients can resume normal activities shortly after the procedure. While a colonoscopy is more suitable for full cancer screening, a sigmoidoscopy is a less invasive option for specific concerns, such as polyp detection or routine lower colon examinations.
Is a Flexible Sigmoidoscopy Painful?
Unsurprisingly, many people worry about whether the procedure will hurt. The good news is that a flexible sigmoidoscopy is not usually painful. Patients may experience mild discomfort, such as cramping, pressure, or bloating—particularly when air is introduced to inflate the colon for better visibility.
Temporary Discomfort: Since the procedure is brief and typically performed without sedation, any discomfort is short-lived and manageable. If you are anxious or have a low pain threshold, your doctor can suggest measures to help you relax or alleviate discomfort beforehand.
How to Prepare for a Flexible Sigmoidoscopy
Preparation is key to the success and accuracy of the examination. Some patients are advised to follow a “clear liquid” diet the day before the test, including broths, clear juices, tea or coffee (without milk), and gelatin.
To clear the lower bowel, you may be instructed to use a drugstore enema or take a mild laxative a few hours before the test. If you are on medication—particularly blood thinners or diabetes drugs—inform your doctor, as they may adjust your dosage or timing temporarily.
Full compliance with these guidelines ensures clear visibility during the examination and avoids the need for a repeat procedure.
What to Expect During and After the Procedure
When the procedure day shows up you will be instructed to lie on your left side. The doctor will gently insert the lubricated sigmoidoscope into your rectum. A small amount of air may be introduced to expand the view, which can cause a sensation of fullness or the urge to pass a bowel movement.
The test usually takes under 20 minutes. Afterwards, you might feel slightly bloated or pass gas—both temporary side effects as your body expels the air used during the procedure. Soon after, the majority of people are able to resume their regular activities.
Serious complications are rare, but if you experience severe pain, heavy bleeding, or signs of infection, seek medical attention immediately.
Conclusion
Your GP (general practitioner) may refer you for a flexible sigmoidoscopy to diagnose various lower bowel conditions with minimal preparation or recovery time. Whether you have long-term digestive issues or require regular screening, this procedure can provide essential insights.
If you are experiencing rectal bleeding, bloody stools, persistent changes in bowel habits, or unexplained abdominal pain, do not delay. Schedule an appointment with our experts to determine if a flexible sigmoidoscopy is right for you.
Chase Lodge Hospital
