How long does a colonoscopy take?

A colonoscopy is the best way to screen for colorectal cancer. Everyone at average risk for the disease should start getting them at age 45.

If you’re scheduled for your first colonoscopy, you may be wondering what to expect and how much time it will take. While the procedure itself could take as little as 20 minutes, once you factor in the prep and recovery time, the experience does take longer.

We spoke with gastroenterologist Mazen Alasadi, M.D., to learn more.

Preparing your colon for the procedure

Your colon is normally filled with stool, so it must be cleaned out completely before a colonoscopy is administered. You’ll be put on a diet of only clear liquids 24 hours before your procedure, but you must stop consuming any liquids at least two to four hours before your procedure. Acceptable liquids are ones you can see through, such as water, Gatorade, broth, and coffee without milk or creamer.

“For patients with constipation or those who do not have regular bowel movements, I give them 48 hours on the liquid diet,” says Alasadi.

In addition, the night before your colonoscopy, you will need to start drinking a prep solution which you will consume in two rounds – half on the evening before the procedure and the other half on the morning of the procedure. The prep solution is a laxative, so you’ll use the bathroom several times to clean the stool out of your colon. You should finish drinking it at least two to four hours before the procedure.

What to expect when you arrive for your colonoscopy

You’ll usually be asked to arrive at the hospital an hour ahead of your procedure. So, if your colonoscopy is scheduled for 8 a.m., you’ll need to arrive at 7 a.m.

“During this time, the nurse will ask if you’re experiencing any pain or other health issues, and whether you have any questions,” says Alasadi. “Then you’ll change into your hospital gown before being taken into the room where you’ll be administered anesthesia through an IV.”

Most patients will be put under deep sedation for their colonoscopy, but some patients will need general anesthesia. An anesthesiologist or CRNA will remain inside the room to monitor your oxygen levels, blood pressure and heart rate throughout the procedure.

“Sometimes the colonoscopy takes 20 minutes; sometimes it can take an hour,” says Alasadi. “It depends on how many polyps we find and how easily we’re able to examine the colon.”

What to expect when you complete your colonoscopy

After the colonoscopy is completed, you’ll move to a recovery area where you’ll remain for about 30 to 45 minutes while you fully wake up from your sedation. Nurses will make sure your vital signs are stable and monitor you until the sedation wears off. Snacks are available in the recovery area.

Your gastroenterologist will explain what, if anything, they found during the colonoscopy and provide information about your visit. This is a good time to ask questions.

Once the sedation has fully worn off, you’ll be taken to your car in a wheelchair, and someone must be available to drive you home. If you are using a rideshare app, you must be accompanied by a responsible adult.

“From the time you arrive at the hospital until the time you leave, it’s usually between two-and-a-half and three hours,” says Alasadi.

When to resume normal activities

Once you return home after your colonoscopy, it’s a good idea to rest.

“You shouldn’t drive, operate heavy machinery or do any kind of accounting or financial work,” says Alasadi. “Just take it easy.”

It is usually OK for you to eat after your colonoscopy procedure. In some cases, if you have a lot of large polyps removed, your doctor may place you on a restricted diet. But most patients can return to their normal diet right away.

Typically, you can return to normal activities the day after your procedure. This includes driving and going to work.

If no polyps were found during your colonoscopy, you won’t need another one for another 10 years. In certain situations, your doctor may recommend you get your next colonoscopy sooner, so be sure to follow your doctor’s instructions.

Request an appointment at MD Anderson online or by calling 1-877-632-6789.