Preparing for a Colonoscopy

The Purpose of Colonscopy

During a colonoscopy, the colon and rectum are examined for signs of disease such as inflammation, ulcers, polyps, and cancer. During the procedure the patient is lightly sedated. A doctor inserts a colonoscope into the anus. The colonoscope is a long, thin, flexible tube fitted with a light source and a miniature camera.

The tube is guided through the rectum and colon to the beginning of the small intestine, and the camera transmits images to a computer screen, allowing the doctor to make a close examination. Once the colonoscope reaches the beginning of the small intestine, the tube is slowly removed as the doctor examines the colon and rectum for a second time.


There are several things which must be done to properly prepare for a colonoscopy. Most doctors will provide written instructions on how to prepare for the procedure.

Before the procedure, it’s important to tell your doctor about any pre-existing medical conditions you have, such as lung or heart conditions, allergies to medication, and any medications you are taking. Pregnant women must also make sure the doctor knows of the pregnancy prior to the procedure.

In addition your doctor may provide some dietary restrictions to follow for a few days before the colonoscopy. You may be asked to limit your intake of solid food, and to take some laxatives to help clean your colon.

Just before the procedure you will be given at least one enema, to further clean the colon. You will probably be asked to hold the enema solution in for several minutes to help the cleansing process. This is important because the bowel and colon must be as empty as possible so that the doctor can have a clear view when examining your digestive tract.

After the Procedure

A colonoscopy usually takes between thirty and sixty minutes. You may be required to stay for an hour or two after the procedure is complete, to ensure there are no complications. You may feel some bloating or cramping for a short time.

The colonoscopy is an outpatient procedure, and you will usually be sedated. This means you’ll need someone to drive you home after the procedure, as it’s unsafe to drive or operate machinery for several hours after the sedative.

Recovery is usually very quick, and you can typically resume normal activities and diet the day after the colonoscopy.

Complications of colonoscopy are rare. If you experience any severe abdominal pain, fever or chills, or rectal bleeding, contact your doctor, as these symptoms may indicate potentially dangerous complications.


Colonoscopy information at the National Institute of Diabetes and Digestive and Kidney Diseases at the National Digestive Diseases Information Clearing House.

The Mayo Clinic on Colonoscopy