All About Colonoscopy: Preparation and Procedure

What to expect before and during the procedure.

Colonoscopy is a visual examination of the lining of the rectum and the colon with a flexible fiber-optic endoscope.

Procedure Preparation
The rectum and colon must be completely empty of stool in order to adequately perform the colonoscopy procedure. The following recommendations may be made by your physician:

  • In some cases, an enema is done either the day before or on the day of the procedure
  • Upon physician request, you may be asked to stop eating and drinking after midnight prior to your exam
  • You may receive an oral preparation the day prior to your scheduled procedure
  • You should have nothing to eat or drink (6 to 12 hours) before the test

Note: It is essential that you follow your physician’s instructions fully in regards to your preparation. Failure to follow instructions may result in rescheduling the procedure at a later date. We may request that you arrive one hour prior to your scheduled time in order to be adequately prepared for the procedure.

Preparation at the Facility
Removable items in your mouth such as dentures, tongue rings and partials will require removal. An intravenous line (IV) will be placed in your arm to deliver medications for comfort during the procedure. You will be attached to a monitor to check your blood pressure, heart rate and oxygen status.

During the Colonoscopy
In order to properly advance the colonoscope through the large intestine, you will be instructed to lie on your left side. The lining of the rectum and colon will be examined closely. If necessary, polyps may be removed and biopsies may be obtained through the endoscope. When the area has been viewed and any tissue samples taken, the endoscope will be removed. The procedure usually lasts 15 to 60 minutes. In rare instances, the entire colon may not be well visualized due to difficulties in advancing the scope or stool still present. The physician may need to repeat the procedure at a later date or discuss an alternative treatment plan.

How It Feels
Throughout the colonoscopy procedure, there may be a sensation of pressure, gassiness, bloating or cramping at various times. You may have a sensation of the scope moving in the colon. A nurse will observe you closely during the procedure to monitor your comfort level.

Results
Due to the effects of sedation from the medication you received, the physician may speak with your family or delay his talk with you. The physician’s discussion may involve a postprocedure phone call or a postprocedure follow-up visit. Please note that it may take several days to a week before your physician receives the results of any biopsies taken.

Find a San Diego Gastroenterologist
To find a Sharp-affiliated doctor, search for a San Diego gastroenterologist or call 1-800-82-SHARP (1-800-827-4277), Monday through Friday 8 am to 6 pm.

For More Endoscopy Information
To find general health information about endoscopy, visit Digestive Disorders in Adult Health or read the Digestive Disorders News archive. 

This information has been prepared by the Sharp Memorial Outpatient Pavilion team for patients in their unit. Colonoscopy preparation and procedure may vary depending on location.