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Peninsula Gastroenterology Medical Group, Gastroenterologists
Redwood City: 2900 Whipple Ave | Suite 245 |Redwood City, CA 94062 • Phone: 650-365-3700
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What is a Colonoscopy?

Colonoscopy enables your doctor to examine the lining of your colon for abnormalites by inserting a flexible tube as thick as your finger into your anus and slowly advancing it into the rectum and colon.

What Happens During a Colonoscopy?

Colonoscopy is well-tolerated and rarely causes much pain.  You might feel pressure, bloating or cramping during the procedure.  Your doctor might give you a sedative to help you relax and better tolerate any discomfort.

You will lie on your side or back while your doctor slowly advances a colonoscope through your large intestine to examine the lining.  Your doctor will examine the lining again as he or she slowly withdraws the colonoscope.  The procedure itself usually takes 15 to 60 minutes, although you should plan on two to three hours for waiting, preparation and recovery.

In some cases, the doctor cannot pass the colonoscope through the entire colon to where it meets the small intestine.  Although another examination might be needed, your doctor might decide that the limited examination is sufficient.

What if the Colonoscopy Shows Something Abnormal?

If your doctor believes that an area needs further evaluation, he or she will pass an instrument through the colonoscope to obtain a biopsy for analyzation.  Biopsies are used to identify many conditions, and your doctor might order one even if he or she doesn't suspect cancer.  If a colonoscopy is being performed to identify sites of bleeding, your doctor might control the bleeding through the colonoscope by injecting medications or by coagulation.  Your doctor might also find polyps during the procedure, and he or she will most likely remove them during the examination.  These procedures don't usually cause any pain.

What are Polyps and Why are They Removed?

Polyps are abnormal growths in the colon lining that are usually benign.  They vary in size from a tiny dot to several inches.  Your doctor can't always tell a benign polyp from a malignant polyp by its outer appearance, so he or she will send removed polyps for analysis.  Because cancer begins in polyps, removing them is an important means of preventing colorectal cancer.

What Happens After a Colonoscopy?

Your physician will explain the results of the examination to you, although you'll probably have to wait for the results of any biopsies performed.  If you were given sedatives during the procedure, someone must drive you home and stay with you.  Even if you feel alert after the procedure, your judgment and reflexes could be impaired for the rest of the day.  You might have some cramping or bloating because of the air introduced into the colon during the examination.  This should disappear quickly when you pass gas.

What are the Possible Complications of a Colonoscopy?

Colonoscopy and polypectomy are generally safe when performed by doctors who have been specially trained and are experienced in these procedures.

One possible complication is perforation, or tear, through the bowel wall that could require surgery.  Bleeding might occur at the site of biopsy or polypectomy, but it's usually minor.  Bleeding can stop on its own or be controlled through the colonoscope; it rarely requires follow-up treatment.  Some patients might have a reaction to the sedatives or complications from heart or lung disease.

Although complications after a colonoscopy are uncommon, it's important to recognize early signs of possible complication.  Contact your doctor if you notice severe abdominal pain, fever and chills, or rectal bleeding of more than one-half cup.  Note that bleeding can occur several days after polypectomy.

Copyright 2004 American Society for Gastrointestinal Endoscopy

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Atherton Endoscopy Center

While you are a patient at Atherton Endoscopy Center, our highly competent and professional staff will care for you. Everyone from the receptionist to the physician embraces our philosophy of patient-focused care. Above all, our staff is friendly and concerned for your comfort.