Colonoscopy is a procedure that uses a long, flexible, narrow tube with a light and tiny camera on one end, called a colonoscope or scope, to look inside the rectum and entire colon. Colonoscopy can show irritated and swollen tissue, ulcers, and polyps.
A colonoscopy is performed to help determine the cause of:
Screening & Prevention
Colonoscopy is the most common method of screening for colon cancer. The American Cancer Society (ACS) recommends routine screenings for people 45 and over. Most colon cancers begin as polyps. Screening can detect polyps so they can be removed before they become cancerous. Regular screening and removal of any polyps found can reduce your risk of colorectal cancers by as much as 90%.
Colonoscopy saves lives. Gastroenterologists perform colonoscopies to diagnose a number of health problems – including colorectal cancer, which is the second leading cause of cancer-related deaths in men and women in the United States. Fortunately, about 90 percent of people live 5 or more years when their cancer is detected early.
While there are several ways to test for colorectal cancer, most doctors recommend a colonoscopy. This is because colonoscopy is better at detecting polyps, which are growths in the intestine that may turn into cancer. What’s more, a doctor can remove suspicious polyps during colonoscopy, before the polyps turn into cancer.
Frequently Asked Questions about Colonoscopy
How do you prepare for a colonoscopy?
Your gastroenterologist will provide you with specific instructions on preparing for a colonoscopy; it is essential to follow these instructions closely. In most cases, the digestive doctor will recommend that you eat a low-fiber diet for a few days before your colonoscopy; avoid eating whole grains, nuts or seeds, raw fruits, dried fruit, or vegetables. Your doctor will likely recommend a clear liquid diet the day before a colonoscopy. Do not eat or drink anything two hours before your colonoscopy unless otherwise directed by your gastroenterologist.
The day before your colonoscopy, you will drink a bowel-cleansing liquid that will induce diarrhea. The exact colonoscopy prep used depends largely on the product your gastroenterologist prefers, the time of your colonoscopy, and any prior experience you may have had with a specific product – if one type of bowel prep did not work well for you, your doctor may recommend another.
All patients should:
- Arrange for a ride home, as driving is not allowed for 24 hours following the test.
- Cleanse the bowel completely beforehand.
Your Northeast Digestive Health Center provider will provide written prep instructions prior to your procedure. Following all instructions is very important to ensure accurate results. See all colonoscopy prep instructions.
What can I eat the day before a colonoscopy?
Consume only clear liquids the day before a colonoscopy. Clear liquids are foods and beverages that are transparent and liquid at room temperature.
Examples of clear liquids include:
- Clear broth or bouillon
- Black coffee or tea
- Clear juice, such as apple and white grape)
- Clear sports drinks or soft drinks
The following foods and beverages that are NOT clear liquids, and should NOT be consumed the day before your colonoscopy:
- Ice cream
- Coffee or tea with cream
- Cream soup
- Solid food
How long does a colonoscopy take?
A colonoscopy usually takes about 30 to 60 minutes.
Does a colonoscopy hurt?
No – the healthcare team administers anesthesia prior to starting the colonoscopy, so the patient is asleep and pain-free during the procedure. What’s more, the patient does not remember anything about the procedure.
In some cases, the doctor will introduce air into the patient’s bowel during the procedure. There is a small chance that the patient will feel some gas-like cramping after the colonoscopy. If the doctor takes a small amount of tissue to send to a lab for biopsy, the patient may experience some discomfort the next day.
What can you eat after a colonoscopy?
After a colonoscopy, consume foods and beverages that are easy on your digestive system. Your doctor may recommend that you eat a low-residue diet immediately after the colonoscopy. A low-residue diet usually limits dairy foods and features low-fiber foods that are easy to digest and that produce less stool.
After a colonoscopy, you may consume the following food and drinks:
- Apple butter
- Canned fruit, such as peaches
- Drinks with electrolytes
- Fruit juice
- Graham crackers
- Herbal tea
- Mashed or baked potato
- Saltine crackers
- Scrambled eggs
- Smooth nut butter
- Soft white fish
- Tender, cooked vegetables
- Vegetable juice
- White bread or toast
Drink plenty of fluids to prevent dehydration associated with diarrhea from the bowel prep or from withholding liquids prior to the procedure.
What should I avoid eating after a colonoscopy?
Your doctor may recommend that you avoid eating anything that could upset your bowels, such as spicy foods or foods that are high in dietary fiber. Heavy, greasy foods may make you feel nauseated after receiving anesthesia. If your doctor introduced air into your bowel, you may want to avoid carbonated beverages that add even more gas to your system.
Who should I contact for more information about a colonoscopy?
For more information about colonoscopy and how to prepare for this important procedure, contact our gastroenterologists at Northeast Digestive. We are always glad to answer your questions and schedule an appointment!