What is Flexible Sigmoidoscopy? Purpose, Procedure & Results

Flexible sigmoidoscopy is a medical procedure that lets your doctor examine the lower part of your large intestine using a thin, flexible tube with a tiny camera. This screening test can help detect problems like polyps, inflammation, or early signs of colorectal cancer in the sigmoid colon and rectum.

The procedure takes about 10 to 20 minutes and is less invasive than a full colonoscopy. Your doctor can see the inside of your bowel clearly and take tissue samples if needed. Many people find it more comfortable than they expected, especially with proper preparation and a caring medical team.

What is flexible sigmoidoscopy?

Flexible sigmoidoscopy is a diagnostic procedure that examines the rectum and the lower third of your colon. Your doctor uses a sigmoidoscope, which is a flexible tube about the thickness of your finger with a light and camera at the tip.

The sigmoidoscope can bend and move through the curves of your lower intestine. This allows your doctor to see the inner lining of your rectum and sigmoid colon, which is the S-shaped part of your large intestine. The procedure covers roughly the last 20 inches of your colon.

Unlike a full colonoscopy, sigmoidoscopy only examines the lower portion of your large intestine. This makes it a shorter, less complex procedure that often requires less preparation time. However, it cannot detect problems in the upper parts of your colon.

Why is flexible sigmoidoscopy done?

Flexible sigmoidoscopy serves as both a screening tool and diagnostic procedure for various bowel conditions. Your doctor might recommend it to check for colorectal cancer, especially if you are over 50 or have risk factors for the disease.

The procedure can help identify several conditions in your lower colon and rectum. Your doctor can spot polyps, which are small growths that might become cancerous over time. They can also detect inflammation, bleeding sources, or other abnormal changes in your bowel lining.

You might need this test if you have symptoms like rectal bleeding, changes in bowel habits, or unexplained abdominal pain. Sometimes doctors use it to monitor known conditions like inflammatory bowel disease. It can also help investigate causes of chronic diarrhea or constipation.

What is the procedure for flexible sigmoidoscopy?

The flexible sigmoidoscopy procedure happens in your doctor's office or an outpatient clinic. You will lie on your left side on an examination table, and your knees will be drawn up toward your chest for the best access to your rectum.

Your doctor will first perform a digital rectal exam using a gloved, lubricated finger. Then they will gently insert the sigmoidoscope through your anus and into your rectum. The scope moves slowly through your lower colon while your doctor watches the images on a monitor.

During the procedure, your doctor may pump small amounts of air into your colon to open it up for better viewing. This can cause some cramping or pressure, which is normal. If your doctor sees any polyps or suspicious areas, they can take tissue samples through the scope.

The entire procedure typically takes 10 to 20 minutes. You will be awake during the exam, though some doctors may offer mild sedation if you are particularly anxious. Most people tolerate the procedure well with minimal discomfort.

How to prepare for your flexible sigmoidoscopy?

Preparing for flexible sigmoidoscopy involves cleaning out your lower colon so your doctor can see clearly. Your preparation will be less extensive than for a full colonoscopy, but it is still important to follow all instructions carefully.

You will need to follow a clear liquid diet for 24 hours before your procedure. This means you can have clear broths, plain gelatin, clear juices without pulp, and plenty of water. Avoid solid foods, dairy products, and anything with artificial coloring.

Your doctor will prescribe an enema or laxative to clean out your lower bowel. You might need to use one or two enemas the morning of your procedure, or take oral laxatives the night before. Follow the timing instructions exactly as your doctor provides them.

Let your doctor know about all medications you take, especially blood thinners or diabetes medications. Some medications might need to be adjusted before the procedure. Also mention any allergies or medical conditions that could affect the exam.

How to read your flexible sigmoidoscopy results?

Your flexible sigmoidoscopy results will show what your doctor found in your lower colon and rectum. Normal results mean your doctor did not see any polyps, inflammation, bleeding, or other concerning changes in the examined area.

If polyps were found, your doctor will describe their size, location, and appearance. Small polyps might be removed during the procedure, while larger ones may require a full colonoscopy for safe removal. Your doctor will explain whether the polyps appear benign or need further testing.

Abnormal results might include signs of inflammation, bleeding sources, or suspicious areas that need biopsy. If tissue samples were taken, you will need to wait for pathology results, which usually take a few days. Your doctor will contact you with these results and discuss next steps.

Keep in mind that sigmoidoscopy only examines the lower third of your colon. Even with normal results, your doctor might still recommend a full colonoscopy to screen the entire colon, especially if you have risk factors for colorectal cancer.

What are the risk factors for needing flexible sigmoidoscopy?

Age is the most significant risk factor for needing flexible sigmoidoscopy screening. Most doctors recommend colorectal cancer screening starting at age 45 to 50, even if you have no symptoms or family history of the disease.

Several factors can increase your risk and make sigmoidoscopy more likely to be recommended. These include having a family history of colorectal cancer or polyps, especially in first-degree relatives like parents or siblings. Personal history of inflammatory bowel disease also increases your risk.

Lifestyle factors play a role in your colorectal cancer risk as well. Here are some factors that might prompt your doctor to recommend screening:

• Smoking or heavy alcohol use
• Diet high in red meat and processed foods
• Lack of regular physical activity
• Obesity or being significantly overweight
• Type 2 diabetes

These risk factors help your doctor determine when you should start screening and how often you need it. People with higher risk might need more frequent screening or earlier start dates.

What are the possible complications of flexible sigmoidoscopy?

Flexible sigmoidoscopy is generally very safe, but like any medical procedure, it does carry some small risks. Serious complications are rare, occurring in less than 1 in 1,000 procedures.

The most common side effects are mild and temporary. You might experience some cramping, bloating, or gas after the procedure from the air that was pumped into your colon. These feelings usually go away within a few hours as the air is absorbed or passed.

More serious complications can occur but are uncommon. Here are the main risks to be aware of:

• Bleeding from biopsy sites or polyp removal
• Perforation or tear in the colon wall
• Infection at biopsy sites
• Severe abdominal pain or cramping
• Allergic reactions to medications used

These complications require immediate medical attention. Your doctor will give you specific instructions about warning signs to watch for and when to call for help.

When should I see a doctor for flexible sigmoidoscopy?

You should discuss flexible sigmoidoscopy with your doctor if you are approaching the recommended screening age, which is typically 45 to 50 years old. Even without symptoms, regular screening can catch problems early when they are most treatable.

Certain symptoms warrant prompt evaluation and might lead to a sigmoidoscopy recommendation. Contact your doctor if you experience persistent rectal bleeding, significant changes in your bowel habits, or unexplained abdominal pain that lasts more than a few days.

Other symptoms that might prompt your doctor to recommend sigmoidoscopy include chronic diarrhea or constipation, narrow stools, or feeling like your bowel does not empty completely. Weight loss without trying can also be a concerning symptom that needs investigation.

After your procedure, you should contact your doctor immediately if you develop severe abdominal pain, heavy bleeding, fever, or signs of infection. These could indicate complications that need prompt treatment.