Sigmoidoscopy is the minimally invasive medical examination of the large intestine from the rectum through the last part of the colon. There are two types of sigmoidoscopy, flexible sigmoidoscopy, which uses a flexible endoscope, and rigid sigmoidoscopy, which uses a rigid device.

Colonoscopy
What To Think About, From Healthwise

• In general, pregnant women or people who have severe heart disease, an abdominal infection, or diverticulitis should not have a colonoscopy unless there is an important reason for it.
• Colonoscopy is a more expensive procedure than a barium enema and other endoscopic colon tests (such as proctoscopy or sigmoidoscopy), but it can be done less often over time if results are normal. Colonoscopy is recommended every:
• 10 years for people with normal results.
• 3 to 5 years for people with increased risk factors for colorectal cancer or when problems are found during the colonoscopy.
• Most experts, including the American Gastroenterological Association, recommend that people with no risk factors for colorectal cancer start screening tests at age 50. Fecal occult blood testing (FOBT) or a sigmoidoscopy test may be recommended or a colonoscopy or double-contrast barium enema (DCBE) may be used. If results from FOBT or sigmoidoscopy show a problem, a follow-up colonoscopy is recommended. For more information, see the medical tests Fecal Occult Blood Test, Sigmoidoscopy, and Barium Enema.
• The American Gastroenterological Association recommends that people with risk factors for colorectal cancer start screening tests at age 40. Tests may include FOBT, sigmoidoscopy, barium enema, or colonoscopy. If you are at increased risk of colon cancer, talk to your doctor about which test is best for you and how often you should do the tests.
• Talk to your doctor if you are considering virtual colonoscopy to screen for colon cancer. This procedure is a newer method that uses a CT scan to take two- or three-dimensional pictures of the colon.
• Virtual colonoscopy is less uncomfortable than standard colonoscopy and may be a good test for people with an average risk for colon cancer. However, if you have a virtual colonoscopy and a problem is found, you may need a standard colonoscopy so a biopsy can be done. Virtual colonoscopy may not find small colon polyps as well as a standard colonoscopy.
• For people with a risk for colon cancer, standard colonoscopy may be a better choice because a biopsy can be done or a polyp can be taken out.
• Virtual colonoscopy is not covered by all health insurance plans. Check with your insurance plan before having the test.
• Virtual colonoscopy uses the same colon prep as colonoscopy. For many people, the prep for a colonoscopy is more bothersome than the actual test.

How the Test Will Feel

The sedative and pain medication will provide relaxation and produce a drowsy feeling. A rectal examination usually precedes the test to dilate the rectum and make sure there are no major obstructions. You may have the urge to defecate when the rectal exam is performed or as the colonoscope is inserted.

You may feel pressure as the scope moves inside. Brief cramping and gas pains may be felt as air is inserted or as the scope advances. The passing of gas is necessary and should be expected.

Discomfort may be lessened by taking slow, deep breaths. This will also help relax the abdominal muscles. Mild abdominal cramping and considerable passing of gas may occur after the exam. Sedation should wear off in a few hours. Because of the sedation, you may not feel any discomfort and may have no memory of the test.

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