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Medical Author:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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Medical Editor:

Bhupinder Anand, MD

In this Article

• What is colonoscopy?
• Why is colonoscopy done?
• What bowel preparation is needed for colonoscopy?
• What about current medications or diet before colonoscopy?
• What should I expect during colonoscopy?
• What if there are abnormalities detected during colonoscopy?
• What should I expect post colonoscopy?
• What are the possible complications or alternatives to colonoscopy?
• What is virtual colonoscopy?
• What's new in colonoscopy?
• Patient Comments: Colonoscopy - Describe Your Experience
• Patient Comments: Colonoscopy - Preparation
• Find a local Gastroenterologist in your town
• Colonoscopy Index

What bowel preparation is needed for colonoscopy?

If the procedure is to be complete and accurate, the colon must be completely cleaned, and there are several colonoscopy preparations . Patients are given detailed instructions about the cleansing preparation. In general, this consists of drinking a large volume of a special cleansing solution or several days of a clear liquid diet and laxatives or enemas prior to the examination. These instructions should be followed exactly as prescribed or the procedure may be unsatisfactory (visualization of the lining of the colon may be obscured by residual stool), and it may have to be repeated, or a less accurate alternative test may be performed in its place.

What about current medications or diet before colonoscopy?

Most medications should be continued as usual, but some may interfere with the examination. It is best that the physician is informed of all current prescriptions or over-the-counter medications. Aspirin products, blood thinners such as warfarin (Coumadin), arthritis medications, insulin, and iron preparations are examples of medications that may require special instructions. The colonoscopist will also want to be aware of a patient's allergies and any other major illnesses. The colonoscopist should be alerted if, in the past, patients have required antibiotics prior to surgical or dental procedures to prevent infections. Instructions may also be given to avoid certain foods for a couple of days prior to the procedure, such as stringy foods, foods with seeds, or red Jello.