Low-fiber diet for colonoscopy prep

February 28, 2023

Providence Health Team

[5 MIN READ]

If you’ve never undergone a colonoscopy, chances are you’ve heard about the procedure from a friend or family member. It’s a relatively simple examination that can save your life (it can detect colorectal cancer in the early, treatable stages) — but that doesn’t change the fact that some people find the preparation regimen mildly unpleasant. Your doctor will instruct you to take very specific steps so your large intestine will be in the best possible condition for the examination.

One important step is to eat only low-fiber foods in the days leading up to your colonoscopy. Here, we’ll give you ideas about how you can temporarily change your diet — and we’ll also share some delicious recipes that will have you looking forward to your low-fiber diet.

What is a colonoscopy?

First, however, let’s take a look at the procedure itself. During a colonoscopy, your doctor uses an endoscope — a flexible tube with a lighted camera on the end — to view your large intestine. They will pass the endoscope through your anus and rectum into your colon, and as they are doing so, the camera sends pictures of the inside of your large intestine to a screen.

The procedure doesn’t hurt because your doctor will either use general anesthesia (to put you to sleep) or conscious sedation (to decrease your awareness so you remember little to none of what occurred after the examination).

While the doctor is examining your large intestine, they may take a biopsy or tissue sample. They will also remove any growths, called polyps, that they find. Colon polyps are abnormal growths that can lead to cancer if left untreated. The colonoscopy allows your doctor to stop cancer before it even has a chance to develop — a practice that has saved many lives.

Who should have a colonoscopy?

Until recently, doctors recommended that men and women who are at average risk for colon cancer begin having colonoscopies at age 50. However, in 2017, the American Cancer Society (ACS) published in the Journal of the National Cancer Institute that colorectal cancer rates were rising among young and middle-aged adults.

As a result, the ACS changed its guidelines for colon cancer screening. Now, it recommends that average-risk individuals start screening for colon cancer at age 45, with repeated colonoscopies every five years if the doctor finds few to no polyps during the examination. People younger than 45 who are at increased risk for colorectal cancer — such as people with a family history of colorectal cancer or African Americans — should talk to their doctor about earlier screening for their risk factors.

So, if you are 45 or older and have never had a colonoscopy, now is the time to get informed.

How to prepare for a colonoscopy

There are three major steps to preparing for a colonoscopy:

1. Eating a low-fiber diet for two or three days before the procedure.

2. Switching to a clear liquid diet on your last day of preparation.

3. Drinking a laxative formula the night before the colonoscopy for bowel preparation.

Your doctor will likely give you detailed instructions for how to prepare. In many cases, doctors want you to reduce the fiber in your digestive tract to help the bowel cleanse run smoother. Your doctor needs to see your colon clearly during the procedure, and fiber can prevent that from happening.

So, what does a low-fiber diet look like? You should look for foods such as:

Cooked vegetables
Refined grains
Chicken, turkey, lamb or lean pork
Eggs
Tofu
Creamy nut butters
Fruit without seeds or skins
Juices without seeds or pulp
Fish and other seafood
Skim or low-fat milk
Potatoes without skin
White rice

Avoid foods such as:

Whole grains
Raw vegetables
Corn, tomatoes, onions
Cucumbers
Brussels sprouts and cooked cabbage
Lima beans
Dried fruit
Coconut and popcorn
Seeds
Nuts and crunchy nut butters
Dried beans or legumes
Granola
Tough meat with gristle
Prunes and prune juice
All desserts containing nuts, seeds, dried fruit or coconut
Tough or chewy cuts of meat

These restrictions may seem like a lot of work, but you can use this as an opportunity to try out new, low-fiber recipes. Of course, you will have to put those recipes aside the day before your procedure, because you will need to be on a clear broth diet.

The night before your colonoscopy, your doctor will prescribe a laxative. Don’t plan anything away from home for that evening, because you will likely be experiencing many bowel movements. The good news is that the more you visit the bathroom, the cleaner your large intestine will be for the procedure!

On the day of the outpatient procedure, you will need someone to drive you to and from your appointment. Once you’ve been released from the hospital or clinic, feel free to eat whatever is most comfortable for you.

Learn more about what to expect from a colonoscopy at Providence.

Find a doctor

You can find a gastroenterologist, general surgeon or other provider who offers colonoscopies in Providence’s provider directory.

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