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What to Eat Three Days Before Your Colonoscopy

Whether this is your first screening or your first since the pandemic started, here is a refresher on how to prep for a colonoscopy from gastroenterologist Dr. Aaron Martin, starting with what to eat three days before to ensure an accurate screening.

Gastroenterologist Dr. Christopher Adkins is relieved that the rate of cancer screenings has now returned to pre-pandemic levels after there was a drastic decline in screenings during the first months of the COVID-19 pandemic. “Getting screened even during the pandemic is safe and potentially life-saving,” Dr. Adkins emphasizes.

Colon cancer, especially, is touted as one of the most preventable cancers with regular screenings, yet it is the third-most-common cancer in both men and women in the United States, says Dr. Adkins, and ranks second only to lung cancer as a cause of death from cancer. Important to note is that guidelines now recommend that colon cancer screening starts for individuals at 45 years of age instead of 50 years of age. “Rates have doubled in 20- to 49-year-olds in recent years,” explains Dr. Adkins. “Those individuals who have a family member with colon cancer may need to start getting screened even earlier and should talk with their doctor.”

Whether this is your first screening or your first since the pandemic started, here is a refresher on how to prep for a colonoscopy from Dr. Adkins’ colleague and fellow gastroenterologist Dr. Aaron Martin, starting with what to eat three days before to ensure an accurate screening, along with what you can expect during and after your procedure.

How does one start prepping for a colonoscopy?

Prep starts 72 hours or about three days before your procedure when you need to start changing your diet to a low fiber and low residue diet. When we’re doing a colonoscopy, we want the colon to be as clean as possible without any food or residue so we can see everything clearly to screen for colon cancer and polyps. We found that people who eat a high fiber or a high residue diet, meaning foods that aren’t easily digested, these foods will show up in their colon during a colonoscopy, so this is why we ask them to avoid those types of foods.

What are some examples of low-fiber foods that ensure a clear colon for the procedure?

I’ll start with some of the foods you want to avoid. The biggest culprits that will show up in a colonoscopy and obscure our view are foods like nuts, seeds and high-fiber cereals. You also want to avoid granola, coconut, dried fruit and fresh fruit with the skin on, like apples and pears, or fruit with seeds, like strawberries and raspberries. Popcorn is another food you want to avoid. Oatmeal, grits and plain corn flakes are types of cereals that are okay, along with cooked fruits, bananas and applesauce.

Can you talk about day-before prep?

The day before your procedure, you are only going to be on clear liquids all day. The more liquid that you can drink, the better, aside from the liquid formula prep you are going to drink the night before your procedure. The more fluids in your system mean the better your chances are of flushing your colon for a better screening colonoscopy.  [Editor’s Note: Take it from one of Jefferson’s patients, who didn’t get a colonoscopy until she was 61 because of how much she dreaded the prep, it’s not as bad as you think.]

Let’s talk about what people can expect on the day of their procedure.

On the day of the procedure, you’re going to come into our endoscopy procedure unit, where you’ll meet with the nurses and have your IV placed, which is how you’ll receive anesthesia for the procedure. Afterward, you’ll also meet the anesthesiologist and the physician who will be doing your procedure. They will talk to you about the procedure, which takes about 30 minutes.

Are there any symptoms to be aware of after the procedure?

We do put some carbon dioxide gas into the colon to expand it to make it easier to get a clear view. This gas is easily released from the colon and we try to take as much air and gas out of the colon as we can while performing the procedure, but some people can experience some gas pains after colonoscopy. This isn’t common but it happens! A nurse can help you position yourself in a way to relieve the gas after your procedure.

Can you go back to eating whatever you’d like after the procedure?

I tell my patients to eat whatever they feel like eating at the time. There’s no reason to ease back into your normal diet or restrict your diet after your screening unless your physician tells you otherwise. Some patients tell me they’re going to grab a cheesesteak immediately afterward.

Any advice for people who feel embarrassed about getting a colonoscopy?

My staff and I are going to do everything possible to ensure a patient feels absolutely comfortable and safe. There are only a few people in the procedure room—it’s generally just myself [the physician], a technician and the anesthesiologist. I also remind my patients that this is something we do every single day. It’s our job to screen for colon cancer and make sure that we are doing the best thing for our patients by catching any kind of colon cancer early. Patients who express embarrassment coming into the appointment usually tell me that they don’t know why they were so scared beforehand and that they built the experience up to be more than what it was and that they’re relieved to be screened.

When will you know the results of the screening?

Immediately after the procedure, I can tell a patient if they have any kind of polyp or anything that we removed. I’ll explain if there are polyps that we need to keep an eye on; others may not require any follow-up at all. If a polyp requires testing, those results typically take about three to five days to come back.

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