A colonoscopy is a test to check your colon for problems. During a colonoscopy, a doctor uses a small tube with a camera at the end to check for polyps, small growths on the inside of your colon.
Most polyps are benign (not cancerous). But colon cancer always develops from these benign polyps. During a screening colonoscopy, your doctor can remove polyps – which keeps benign polyps from becoming cancer or keep cancerous polyps from growing.
Everyone 45 and older should be screened for colon cancer. And the gold standard for colon cancer screening is a colonoscopy.
Even if you don’t have a family history of colon cancer, you may need a screening colonoscopy. The No. 1 risk factor for colon cancer is age.
Preparing for your colonoscopy
To see the polyps well, your doctor needs your colon to be as empty as possible. This means preparing for the screening colonoscopy with a special diet. Your doctor will give you a detailed instruction sheet.
Here’s an overview of what to expect. Five days before your colonoscopy screening, avoid nuts, seeds, whole wheat bread, beans, corn, raw fruits and vegetables with seeds or skin. You will also pick up a laxative from the pharmacy.
To download detailed colonoscopy prep instructions, view the documents in the sidebar.
Two days before the colonoscopy screening, you should stop eating solid food. You can only drink clear liquids (nothing red or purple), and you should not drink alcohol. You should also begin drinking your prescription laxative. You should drink the laxative slowly over the next two days, finishing it about six hours before your procedure.
Two hours before your screening colonoscopy, stop drinking any liquids.
Just before the colonoscopy, your doctor will give you a light sedative. Most people become relaxed and sleepy. You may not remember the procedure. The colonoscopy will take about an hour.
Once the sedation has worn off, you can go home (with someone else there to escort you). The doctor will let you know if any polyps were found, and what the next steps are.
If you have symptoms of colon cancer, your doctor will likely order a colonoscopy. These symptoms may include bleeding and blood in the stool, belly pain and unexplained weight loss.
Most people have no symptoms of colon cancer. And age is the biggest risk factor for this kind of cancer. That’s why everyone between 45 and 75 should be screened for colon cancer. The gold standard for colon cancer screening is colonoscopy. If you’re 76 to 85, talk to your doctor about whether you need a screening colonoscopy.
In order for your doctor to see potential polyps, your colon needs to be as empty as possible. Before the screening colonoscopy, you will follow a special diet from your doctor. This includes drinking a laxative slowly over several days, drinking only clear liquids and avoiding any liquids two hours before your procedure.
Want more detailed instructions? Check the sidebar for your bowel preparation brand.
Before the screening colonoscopy, you will receive a sedative. This will make you very drowsy or even fall asleep. Some people don’t remember their colonoscopy. The procedure is not painful.
The screening takes about an hour. A doctor will use a small tube with a camera on the end to look inside your colon. The doctor will be able to see and remove any polyps, preventing the polyps from turning into cancer.
If your doctor finds a polyp, they will remove it (preventing it from turning into cancer or spreading cancer in your body) and send it for testing. The testing will determine if the polyp is benign (no cancer).
If it’s benign, no further action is needed. If the polyp shows signs of cancer, your doctor will explain the next steps.
RUSH Excellence in Colonoscopy Screenings and Colon Cancer Detection
- Expert endoscopists with national reputations. Our Chicago-area gastroenterologists deal with complex, difficult-to-treat cases every day. We consistently rank among the best in the country for digestive disease care.
- Your guide during prep and procedure. This may be your first colonoscopy, but it isn’t ours. We perform hundreds of colonoscopy screenings every year in and around Chicago. If you have any problems with preparation or recovery, our team is here to help. Call us at (312) 942-5861.
- Support from our whole team. Hopefully, you get a clean bill of health during your colonoscopy. If your doctor does find polyps, you may need follow-up care. RUSH is ready to help you navigate the next steps. A wide range of specialists are available (often with same- or next-day appointments) at many different locations throughout Chicago and the surrounding areas — so you won’t need to go far to get the care you need.