Colonoscopy
Introduction
This page will help you understand what a colonoscopy is, why it is done, how it is done, how to prepare for it, what the risks are, and what to expect after the colonoscopy is performed.
What is a colonoscopy?
A colonoscopy is a procedure to look at the inner lining of your large intestine (colon and rectum) using a small camera on a flexible tube passed through the anus. The camera sends a video which lets the doctor carefully examine the intestinal lining. The exam takes less than an hour and can detect inflamed tissue, ulcers, polyps (small growths) and other abnormal growths. The doctor can remove polyps and have them examined in a laboratory for signs of cancer. However, polyps are common in adults and usally harmless. It is important to remove these since most colorectal cancer begins as a polyp.
Why is a colonoscopy done?
A colonoscopy is used to help diagnose changes in bowel habits, sudden, unexplained weight loss, abdominal pain, bleeding from the anus, and to identify other intestinal problems. Also, if you are age 50 or older (depending upon your family history), your doctor may recommend a colonoscopy as a procedure to screen for colon cancer. Screening for colon cancer is important since symptoms rarely show up until much later in the disease.
How do I know if I need a colonoscopy?
Routine colonoscopy should begin at age 50 for most people to look for early signs of cancer - earlier if there is a family history of colorectal cancer, a personal history of inflammatory bowel disease, or other risk factors. The doctor will advise you based on your condition and history. As a general rule, if you are over age 50, you will need a colonoscopy every 10 years until the age of 75 or 80, since the biggest risk factor for colon cancer is age. However, if you have a family history of cancer or other risk factors, you will need a colonoscopy earlier and more frequently due to the increased risk of cancer. If you have questions, discuss them with your doctor.
When should I call my doctor?
• If you notice blood in the stool or rectal bleeding
• If you notice a change in your bowel habits such as long-lasting diarrhea or worsening constipation
• If you notice long-lasting, unexplained abdominal pain
• If you notice significant, unexplained weight loss
• If you are over the age of 50, as a screening exam for colon cancer
• If you have a family history of colon cancer or a history of colon polyps or colon cancer
How do I prepare for a colonoscopy?
To prepare for a colonoscopy, you will need to clean out (empty) your colon. This means taking a laxative the night before your exam. A laxative is a medicine that loosens stool and increases bowel movements. This process is called a bowel prep. If your colon is not completely empty, the doctor may not be able to see clearly and could miss something including polyps (small growths) that need to be removed. Your doctor will give you a specific set of written instructions that you must carefully follow in order to prepare for the procedure. These may include:
• Following a special diet the day before the exam
• Taking a laxative the night before the exam
• Adjusting your medications
• Limiting or eliminating solid foods before the exam
• In some cases using an enema kit
During the preparation period, make sure toilet facilities are nearby. You may also want to have petroleum jelly or moist towelettes for cleaning the anus. These will help to improve your comfort level.
What about my medications or my diet before colonoscopy?
Before a colonoscopy, let your doctor know about any special medical conditions you have and any medications that you are taking. You may be asked to stop taking certain medications, like those that thin the blood, such as Coumadin, or non-prescription medicines like aspirin and iron supplements. If your doctor instructs you to stop taking certain medications, it's important to do so.
What should I feel during and after a colonoscopy?
Since you will be sedated (asleep) during the examination, you will feel no pain or even recall most of the procedure or even much of the time after the procedure. Since you will be sedated during the procedure, make sure you arrange for a driver to bring you home. It is not safe for you to drive or operate machinery for about 12 hours after the procedure.
What happens after colonoscopy?
After colonoscopy, your doctor will explain the results. If some tissue has been removed (biopsy) for purposes of diagnosis, results will not be available for a day or so. If you have been sedated during the procedure, you will be observed until most of the effects of the sedation have worn off. Since you were sedated, it is not safe for you to drive and you must have someone drive you home. You may have some cramping or bloating because air is introduced into the colon during the examination. This should disappear after you pass gas. Generally, you should be able to eat after you are discharged, but your doctor may restrict your diet and activities.
What are the possible complications or risks to colonoscopy?
On the whole, colonoscopy is a very safe procedure. It is estimated the overall risk of complications for a routine colonoscopy is about 3.5 per 1,000. Even when a polyp (small growth) is removed, the risk is only about 2 per 100. However, as with any medical procedure, complications can occur. There is a small risk of bleeding (about 1 out of every 1,000 cases). In most cases, the bleeding stops on its own. However, if the bleeding is severe, it may require medical intervention. Perforation (a tear or a hole in the intestine) is probably considered the most severe of all colonoscopy complications. Mild cases can be treated with antibiotics, monitoring, and bowel rest. Allergic reaction and respiratory problems from anesthetic medication can include nausea, vomiting, low blood pressure, and reaction at the injection site. These are rare but are possible risks due to anesthesia. These risks are minimized by following standard dosage procedures and using monitoring equipment to identify problems before they become serious.
If you develop any of the following symptoms, contact your doctor immediately:
• Severe abdominal pain
• Fever
• Bloody bowel movements
• Dizziness
• Weakness
Key Summary Points
• Overall, colonoscopy is a safe procedure.
• A colonoscopy is a procedure used to see inside the colon and rectum.
• All solids must be emptied from the gastrointestinal tract by following a clear liquid diet for 1 to 3 days before a colonoscopy.
• During a colonoscopy, a sedative, and possibly pain medication, will help keep you relaxed.
• A doctor can remove polyps and biopsy abnormal-looking tissues during colonoscopy.
• Driving is not permitted for 12 hours after colonoscopy to allow the sedative time to wear off.
Where can I find additional information?