This sheet of information is to help you become informed about a procedure called flexible sigmoidoscopy. You may have heard about this in association with the tumor that was found in President Reagan’s bowel. Should you have any questions after reading this sheet, please feel free to discuss them with your physician. In 1995, the United States Preventative Services Task Force, which has very stringent guidelines for approval of screening tests, agreed with the recommendation below. All other organizations essentially promoted this test long ago. In 1998, Medicare began paying for flexible sigmoidoscopy even if it was done only for screening.


To identify and diagnose lesions of the bowel at an early stage to prevent cancer;
To find cancer that may already be developed in earlier stages so that it might be more beneficially treated.

Who Should Be Screened?

Any person 50 years of age and older. Flexible sigmoidoscopy is done every 5 years along with cards that check for blood in the stool every year. (If a colonoscopy is done, it is repeated in ten years.).
Those who experience a change in bowel habits (constipation or diarrhea that persists).
Those with rectal bleeding of any sort.
Those who have a stool specimen that tests positive for blood (positive “guaiac” or “hemoccult”).
Those with unexplained weight loss or fevers.
Those who are anemic.
Those who need follow-up of previous polyps or cancers.
Those in high-risk groups who may need to be screened before age 50 (previous cancer, history of ulcerative colitis or Crohn’s, history of female genital cancer, family history of cancer, history of multiple polyps, history of a family member diagnosed with colon polyps or colon cancer before age 60). High-risk groups should begin screening at 35-40 years of age and will most likely require colonoscopy or an x-ray (barium enema) along with the flexible sigmoidoscopy..

What are the Benefits of Screening?

Colon cancer is the second most common cause of cancer death in the United States, being surpassed only by lung cancer. There are 35,000 lives per year that could be saved by early diagnosis. It has now been fairly well documented that cancers begin as small polyps or growths in the colon. It takes somewhere between 5 and 10 years before these benign polyps become cancerous. If these polyps can be detected early and removed, cancer can be prevented. If polyps are found in the lower part of the bowel, this can indicate an association with polyps higher up in the bowel, or with other cancers. Therefore, a screening procedure can identify those patients who need a more extensive procedure called colonoscopy. If all polyps are removed and a vigorous screening program is initiated, the chance of colon cancer is decreased to only 15% of what is predicted for an unscreened population. 90% of patients who are found to have colon cancer on a screening exam (i.e., no symptoms) are alive 5 years later. Compare this to 30-40% of patients who are alive in 5 years if they develop symptoms first.

There is a debate as to what the best screening method is for someone who is not at risk and has no symptoms. In our office, we do the flexible sigmoidoscopy at 50 and 55 years of age, then recommend colonoscopies after age 60..

What is Done?

The procedure of “flexible sigmoidoscopy” is easily carried out in a physician’s office. The appointment is scheduled for 30 minutes but the procedure itself only takes 5-10 minutes. The patient generally lies on a flat table on his/her left side. The physician does a rectal exam, trying to feel for any growths, and then he inserts the instrument called a flexible sigmoidoscope. This is a small tube approximately 1/2″ in diameter. It is about 24″ (60 cm) long and is actually quite movable, like a small piece of tubing. The physician can control the movement with dials at one end. He can make the scope go up and down and to the right or left. The end of the tubing has a small hole for lighting, another for sucking up any fluid that might be left in the bowel, and another one for inserting air. By gently manipulating this tubing, the physician can insert it into the rectum and look at the lower part of the bowel called the sigmoid colon and the left descending colon.

How Much Pain is Involved?

The discomfort is generally quite minimal. Most of it will feel like you are having gas cramps, because the physician does need to inflate the colon with air so that he can see the inside. Most people compare it to a slightly uncomfortable bowel movement. Occasionally, if the bowel really has a lot of loops, there will be added pain, but this is unusual. Women who have had a hysterectomy may be a little more uncomfortable. No medication is generally needed before the procedure or afterwards, unless a patient feels particularly anxious and requests it. Many prefer to take (4) 200 mg ibuprofen (Advil, Nuprin or Motrin) 1½ to 2 hours prior to the procedure. This is acceptable. The patient is generally able to come straight from work and return to work after the procedure.

How Does One Prepare for the Procedure?

Usually, one or two cleansing enemas (Fleets) 30-90 minutes prior to the procedure should be sufficient. If you notice that the fluid is not clear, occasionally a third enema is needed. Inactive, elderly, or a laxative-dependent patient may require 24 hours of clear liquids, as well as four Dulcolax tablets the night before. This is rarely recommended, but if you think this may be needed, use it. If at all possible, no aspirin should be taken for the two weeks prior to the procedure. If you have taken aspirin, or if you are on any medication, please notify the doctor.

When Should the Procedure NOT be done?

In some instances, if you are having severe enough abdominal pain to be admitted to the hospital, the procedure should not be done. Your physician will need to be the guide for this. Likewise, if you are pregnant, have had a recent heart attack, or have some other significant medical disease, you should let your physician evaluate this prior to proceeding with the procedure. If you have an artificial heart valve or an artificial joint, you should receive antibiotics prior to the procedure. Some heart murmurs also require antibiotics. Please alert the physician at the time of the visit and discuss these issues with him.

What are Possible Complications?

It is reassuring to know that the procedure of flexible sigmoidoscopy is relatively safe. Approximately one time out of 10,000 procedures, a tear could be made in the bowel wall. This may require further surgery. Very rarely, there may be some bleeding. Generally, there is little discomfort, but occasionally this is a little more bothersome. In some people who get lightheaded when they see blood or are under stress, fainting is a possibility. (If you are one of these, inform your physician and he can prescribe medicine to prevent this.)

Possible Biopsy

In instances where your physician sees a lesion, he may want to take a small sample of the tissue (biopsy). This will be sent to the pathologist to look at under the microscope and define what it is. This would increase your chance of bleeding a small amount, but, again, it is usually negligible. You cannot feel this. It will not hurt. There are four types of polyps. One type (hyperplastic) is like a skin tag and has no association with cancer. The other three are associated with cancer (adenomatous types), and further diagnostic intervention will be needed.


The charge for flexible sigmoidoscopy alone is $________ plus an office charge if you are a new patient. If it is done totally for the purpose of screening, your insurance company may not cover the charge. However, if you have any symptoms at all, insurance companies generally will provide coverage. Medicare will now also cover screening.

If a biopsy is taken and sent to the pathologist, you will receive a separate bill directly from the lab for analyzing this specimen. Be sure to call us if you haven’t received the results by two weeks after the procedure.

Additional questions and/or concerns can be answered by your physician. Please discuss them with him/her.

Republished with the permission of John L. Pfenninger, M.D. –