Digestive Disorders Health Center

How To Prepare

Anoscopy

Usually, no preparation is needed for an anoscopy.

Proctoscopy and sigmoidoscopy

Test preparation for a proctoscopy and sigmoidoscopy may be similar. Before the test:

• Talk with your doctor to find out if you need to stop taking some medicines, such as warfarin, before the test.
• Tell your doctor if you have been diagnosed with peritonitis, diverticulitis, or toxic megacolon or if you have had recent bowel surgery.

The preparation for these tests usually involves a thorough cleaning of the lower colon, because it must be completely clear of stool (feces). Even a small amount of fecal material can affect the accuracy of the test.

• You may be instructed to follow a liquid diet for 1 to 2 days before the test.
• You may be instructed to not eat for up to 12 hours before the test.
• You may need to have an enema the night before the test and another enema an hour before the examination.
• You may not need special preparation, especially if you have watery or bloody diarrhea.

Talk to your doctor about any concerns you have regarding the need for this test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

How It Is Done

You will usually lie on your left side during the test. You may also be asked to kneel on the table with your bottom raised in the air.

Once you are in position:

• Your doctor will gently insert a gloved finger into your anus to check for tenderness or blockage. For men, your doctor will also check the condition of the prostate gland.
• The lubricated scope is then inserted. The scope is moved slowly forward into the rectum and lower colon. During a sigmoidoscopy, puffs of air sometimes are blown through the scope to open the colon so that your doctor can see more clearly.
• Suction may be used to remove watery stool, enema liquid, mucus, or blood through the scope.
• Once your doctor has moved the scope forward as far as possible, it is slowly withdrawn while tissue is carefully inspected.
• Your doctor may also insert tiny instruments (forceps, loops, swabs) through the scope to collect tissue samples (biopsy) or to remove growths. Tissue samples may be sent to a laboratory for examination.

See the following pictures:

• Step 1: The sigmoidoscope is inserted .
• Step 2: The doctor examines the wall of the sigmoid colon .

After the scope is removed, your anal area will be cleaned with tissues. If you are having cramps, passing gas may help relieve them.

The entire examination usually takes 5 to 15 minutes, slightly longer if tissue samples are taken or if polyps are removed.

If you received a sedative during the test, do not drive, operate machinery, or sign legal documents for 24 hours after the test. Arrange to have someone drive you home after the test.

After the test you may resume your regular diet, unless your doctor gives you other directions. Be sure to drink plenty of liquids to replace those you have lost during the preparation for the sigmoidoscopy.