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Flexible Sigmoidoscopy

What is a flexible sigmoidoscopy?
Flexible sigmoidoscopy is an examination of the inside of the rectum and the lower part of the colon (large intestine). A flexible, lighted tube called a sigmoidoscope is inserted into the rectum and advanced into the colon, allowing the doctor to examine the lining of the lower 30 inches of the colon.

Why should I have flexible sigmoidoscopy?
Flexible sigmoidoscopy is done for several reasons. One is to evaluate symptoms, such as rectal bleeding, abdominal pain, or change in bowel habits. Another reason is to detect colon polyps or colon cancer. Most colon cancer begins in polyps (benign growths in the lining of the colon). Studies show that up to 70% of all polyps occur in the lower portion of the colon. If polyps are detected, they are removed in a later procedure, which helps prevent cancer.

What happens during flexible sigmoidoscopy?
You will either be lying on your left side with your knees slightly drawn up towards your chest or lying on your abdomen in a kneeling position with the head of the table lowered. The doctor will first do a digital exam by inserting a gloved finger into the rectum. The sigmoidoscope, a flexible instrument about the diameter of a finger, is then inserted into the rectum and advanced into the colon so the doctor can see the lining of the colon. It is necessary to inflate the colon with air to visualize the entire lining, which may result in some cramping. Most of the cramping is relieved by the removal of the instrument and air. A biopsy or culture may be taken to diagnose any questionable or abnormal areas or growths. These are done quickly and painlessly during the exam. The entire procedure should take no more than 10 minutes when done by an experienced examiner. You will be able to drive yourself home. Most people find that they can go about their normal daily activities.

How do I prepare for flexible sigmoidoscopy?
You need to use two Fleet enemas. Be sure you do not use mineral oil enemas. On the day of your exam, take one enema two hours before and another an hour before your exam. You may have regular meals and all the fluid you want. It is advisable, in fact, to have something to eat beforehand.

Please tell your doctor ahead of time if you have bleeding tendencies, are taking anticoagulant medications (blood thinners), or have been told to take antibiotics before dental work or diagnostic exams.

When can I get the results from the exam?
Immediately following your exam, your doctor will explain the results. Any biopsies or cultures taken during the exam will be sent to a laboratory where a pathological study of the specimen will be done. Accurate results often take 48 hours or more. You will be notified of the results of these tests. You will receive a separate charge from the laboratory for such studies.

Are there complications?
Sigmoidoscopy is a safe procedure with very low risk when performed by doctors who are trained and experienced. However, there are rare complications, such as bleeding and perforation. Notify your doctor if you have any of the following:

  • Severe pain
  • Vomiting
  • Temperature greater than 101 degrees
  • Bright, red blood greater than 2 tablespoons

Learn more about Flexible Sigmoidoscopy  from the National Digestive Disease Information Clearinghouse (NDDIC) Website