Understanding Flexible Sigmoidoscopy

Flexible sigmoidoscopy (FS) is a medical procedure that enables doctors to view the interior of the rectum and lower colon. They will often order this test to find the cause of abdominal pain or rectal bleeding. It also helps them to diagnose bowel conditions characterized by inflammation or ulcers. Additionally, during an FS procedure, doctors can identify and excise polyps – small, benign clumps of cells – that are potentially cancerous.

What Does the Procedure Involve?

Flexible sigmoidoscopy provides views of the interior of the rectum and sigmoid colon. This is the lower part of the colon. Your doctor will ask you to recline on one side while he or she inserts a narrow, flexible tube, called a sigmoidoscope, into the anus and guides it slowly through the rectum and lower colon. The FS scope gently puffs air into the interior to enhance visibility and ease the progress of the tubing.

The scope is equipped with a miniature camera, which transmits images to a digital screen. If polyps are present, the doctor can remove them with specially designed tools introduced through the scope. Although polyps are common and benign, they sometimes become cancerous, and removing them during an FS procedure is an effective preventative measure.

The doctor may opt to take tissue samples for further lab evaluation. Typically, you will feel no pain during tissue removal. If any bleeding occurs as a result, the physician stops it with a tiny probe or the appropriate medication passed through the scope.

Once the end of the scope reaches the next section of the colon, called the transverse colon, the physician slowly withdraws the scope, watching the computer screen carefully for any additional areas for concern. A standard flexible sigmoidoscopy takes about 20 minutes.

Do I Need to Prepare For a Flexible Sigmoidoscopy?

You do need to prepare yourself for FS. Your physician will provide you with complete instructions. Primarily, you must remove the solids from the sigmoid colon and rectal area to make space for the procedure.

Many doctors start their patients on a clear liquid diet one to three days prior to their FS appointment. Some of the liquids this type of diet includes are:

  • Water
  • Clear broth or bouillon
  • Black coffee
  • Plain tea
  • Gatorade or other similar sports drinks
  • Strained, natural fruit juice

A clear liquid diet flushes out your system, emptying the bowels to ensure a trouble-free procedure. Sometimes the physician prescribes a laxative as well. You take the laxative the night before your scheduled FS to loosen up and purge any remaining stools. Often, your doctor will instruct you to complete your preparations by using a gentle enema before leaving home on the morning of the procedure and will administer one at the doctor’s office as well. An enema is composed mostly of warm water that you directly flush into the rectum and then expel.

To summarize, your physician provides you with detailed instructions for FS preparation, and the steps might include:

  • A clear liquid diet one or more days beforehand
  • A laxative the night before the procedure
  • An enema just prior to the procedure

Following preparation instructions carefully will help facilitate a successful procedure.

What About Medications?

If you are taking aspirin, clopidogrel, or other blood thinning medications like heparin or warfarin, it is important that you discuss this with your physician prior to the flexible sigmoidoscopy. If you are using arthritis or diabetes medications, or if you typically take vitamins with iron, you should let your physician know in advance in case it is necessary to discontinue them until after the procedure. The same holds true of all other prescription and over-the-counter preparations you are using.

Because a flexible sigmoidoscopy causes minimal discomfort, most patients do not need pain or relaxation medications during the test. However, if you are especially apprehensive about the FS, be sure to ask your physician about options to help make the procedure more tolerable.

What Happens After the Procedure?

Some patients experience mild cramping after undergoing FS. This is due to the air added to the colon during the procedure. Any cramping you have will usually ease up naturally within a short amount of time. Typically, you will be able to go about the rest of the day normally, returning to work or home, eating regular meals and enjoying your customary activities.

Rarely, patients experience rectal bleeding that continues for a few days after the FS. Other possible complications include severe, persistent abdominal discomfort, vomiting, or fever and chills. If you experience any of these side effects, you should call your physician right away.

If the doctor excised tissue for biopsy during the FS, expect a follow-up call or appointment to discuss the results. In some situations, the doctor will ask that you undergo further testing, such as colonoscopy. This is a more extensive diagnostic procedure that is similar to a flexible sigmoidoscopy but involves the examination of the entire colon. It takes somewhat longer than the FS test, and your physician may recommend general anesthesia during a colonoscopy.