low residue diet for colonoscopy

Low Residue Diet for Colonoscopy [Dietitian’s Guide]

It’s time for colonoscopy prep! This includes following a low residue diet.

If you’re new here, Hi- I’m Brianne. I’m a Registered Dietitian specializing in prostate cancer. A colonoscopy is not only recommended for those diagnosed with cancer but everyone over 45.

Below we review a low residue diet for colonoscopy preparation.


First, let’s review the colonoscopy procedure.

A colonoscopy is a medical procedure used to examine the inside of the large intestine (colon) and rectum.

It involves inserting a thin, flexible tube called a colonoscope through the anus and into the colon. The colonoscope is equipped with a tiny camera and a light, allowing the doctor to visualize the colon’s inner lining on a monitor in real-time.

Of course, you are sedated during this time.

During the procedure, the doctor can detect abnormalities such as polyps, inflammation, or tumors. They may also perform biopsies or remove polyps for further examination or treatment.

Colonoscopies are commonly used for screening, diagnosis, and surveillance of colorectal conditions, including colorectal cancer. They are considered a crucial tool in preventive healthcare, particularly for individuals over the age of 45 or those at higher risk of colorectal diseases.

Often, when one cancer is found, doctors recommend testing for additional cancers. A colonoscopy is the best way to detect colon cancer. 

If you happen to be undergoing a colonoscopy after a prostate cancer diagnosis, be sure to download my Free Guide to Grocery Shopping for Prostate Health to help you on your journey!

It’s essential to follow doctors orders regarding diet prior to procedure. Stool can hide polyps and small cancers. A colonoscopy may need to be repeated if the colon contains stool.

Does a Colonoscopy Check Prostate Cancer?

The colonoscopy itself does not check for prostate cancer.

However, some argue it is an ideal time for the physician to use a digital rectal exam to assess for prostate cancer. So, this will likely vary based on doctor.

Common tests for prostate cancer include:

  • Blood Test
  • Physican Prostate Exam
  • MRI

However, colonoscopies can test for other conditions listed below.

  • Ulcerative Colitis
  • Crohn’s Disease
  • Diverticulitis
  • Diverticulosis
  • Ulcers
  • Bowel Obstructions

What is a Low Residue Diet?

Before diving into what to eat and what not to eat, it’s helpful to understand why you need to follow a low residue diet for a colonoscopy.

Defining Residue: Understanding its Impact on the Colon

It’s crucial to grasp the concept of residue and its significance in the context of colon health before starting a low residue diet.

Residue refers to undigested food particles that pass through the digestive system and accumulate in the colon. While some residue is normal and necessary for proper bowel function, excessive residue can pose challenges, particularly when preparing for medical procedures such as a colonoscopy.

When residue builds up in the colon, it can lead to increased bowel movements, bloating, gas, and discomfort.

For individuals undergoing a colonoscopy, minimizing residue becomes crucial to ensure optimal visualization of the colon and accurate examination results.

Therefore, understanding the impact of residue on colon health lays the groundwork for appreciating the role of a low residue diet in preparation for medical procedures.

Characteristics of a Low Residue Diet

A low residue diet is specifically designed to minimize the amount of undigested food and fiber in the digestive tract, thereby reducing stool bulk and frequency. This dietary approach focuses on consuming foods that are easily digestible and leave minimal residue behind in the colon.

Key characteristics of a low residue diet include:

  1. Low Fiber Content: Fiber-rich foods, such as whole grains, fruits, vegetables, nuts, and seeds, are limited or avoided to decrease stool volume and frequency.
  2. Cooked and Processed Foods: Foods that are cooked, peeled, or processed tend to have lower fiber content and are preferred on a low residue diet. Examples include white bread, white rice, and canned fruits and vegetables.
  3. Lean Protein Sources: Protein is an essential component of a low residue diet and can be obtained from lean sources such as poultry, fish, eggs, and tofu.
  4. Limited Dairy: Dairy products may be included in moderation, but high-fat options should be avoided due to their potential to increase residue formation.
  5. Fluid Intake: Adequate hydration is essential to maintain bowel function and prevent constipation. Clear liquids, water, and herbal teas are encouraged while carbonated beverages and alcohol should be limited.

The terms low fiber diet and low residue diet are often used interchangeably.

Understanding these characteristics is crucial for effectively implementing a low residue diet and achieving the desired outcomes.

Key Principles and Goals of Following a Low Residue Diet

The primary principles and goals of following a low residue diet for a colonoscopy revolve around minimizing residue in the colon to facilitate clear visualization during the procedure.

Some key principles and goals include:

  1. Reducing Bowel Movements: By consuming foods that are easily digestible and low in fiber, individuals can minimize bowel movements and promote bowel rest, which is especially important before undergoing a colonoscopy.
  2. Alleviating Gastrointestinal Discomfort: Many individuals experience bloating, gas, and abdominal discomfort when consuming high-residue foods. Following a low residue diet can help alleviate these symptoms and improve overall comfort.
  3. Optimizing Colonoscopy Preparation: A low residue diet is often prescribed before a colonoscopy to ensure that the colon is adequately cleansed and free of residual stool, allowing for optimal visualization and accurate examination of the colon.
  4. Promoting Compliance and Tolerance: By providing clear guidelines and emphasizing the importance of dietary compliance, healthcare providers can help patients adhere to a low residue diet and minimize any potential adverse effects or complications.

By adhering to these principles and goals, individuals can effectively navigate a low residue diet and prepare for a colonoscopy with confidence and ease.

Benefits of a Low Residue Diet for Colonoscopy Preparation

So, why follow a low residue diet for a colonoscopy? 

Preparing for a colonoscopy can be a daunting task, but incorporating a low residue diet into your pre-procedure regimen can offer numerous benefits.

Minimizing Bowel Movement and Residual Waste

As stated above, one of the primary benefits of adopting a low residue diet before a colonoscopy is its ability to reduce bowel movements and minimize residual waste in the colon.

By consuming easily digestible foods that leave minimal residue behind, individuals can help cleanse their colon more effectively in preparation for the procedure. This can lead to a clearer visualization of the colon during the colonoscopy, ensuring that the doctor can accurately examine the intestinal lining and detect any abnormalities.

Reducing the Risk of Bowel Obstruction or Perforation During Colonoscopy

High-fiber foods, such as fruits, vegetables, and whole grains, can increase stool bulk and pose a risk of bowel obstruction or perforation during a colonoscopy. However, by following a low residue diet and avoiding high-fiber foods, individuals can significantly reduce this risk.

By minimizing the amount of undigested material in the colon, a low residue diet helps ensure a smoother and safer colonoscopy procedure for patients.

Enhancing Colonoscopy Effectiveness and Accuracy

A clear and clean colon is essential for the effectiveness and accuracy of a colonoscopy. Residual waste and debris in the colon can obscure the doctor’s view and make it challenging to detect abnormalities such as polyps or tumors.

By adhering to a low residue diet, patients can help optimize the quality of their colonoscopy by promoting a cleaner and clearer colon environment. This, in turn, enhances the doctor’s ability to detect and diagnose any underlying colorectal conditions accurately.

Incorporating a low residue diet into your colonoscopy preparation not only facilitates the procedure itself but also contributes to better outcomes and peace of mind for patients.

By minimizing bowel movements, reducing the risk of complications, and enhancing the accuracy of the examination, a low residue diet plays a crucial role in ensuring a successful and effective colonoscopy experience.

Timeline of a Low Residue Diet for a Colonoscopy

So, how long should you follow a low residue diet for a colonoscopy?

Well, this may vary for everyone. It’s crucial to follow the instruction of your physician.


The duration for following a low residue diet before a colonoscopy can vary depending on individual factors and the recommendations provided by your healthcare provider.

Typically, healthcare professionals advise following a low residue diet for around 3 to 5 days leading up to the colonoscopy procedure. This timeframe allows sufficient time to reduce the residue in the colon, promoting optimal visualization and examination during the colonoscopy.

It’s essential to follow the specific instructions provided by your healthcare provider regarding the duration and guidelines for the low residue diet. They may tailor the recommendations based on factors such as your medical history, the reason for the colonoscopy, and any pre-existing conditions you may have.

In addition to following the low residue diet, you may also be instructed to undergo bowel preparation, which involves consuming laxatives or other bowel-cleansing agents to empty the colon completely before the procedure. This step is crucial for ensuring a clear and unobstructed view of the colon during the colonoscopy.

Additionally, many doctors will recommend a clear liquid diet the day prior to the procedure. This includes clear broths, clear juices, and gelatin. Check out my article: Liquid Diet for Cancer Patients for specifics of the clear liquid diet.

The morning of the procedure, doctors typically tell you not to eat anything.

Always consult with your healthcare provider for personalized guidance on how long to follow a low residue diet and any other pre-procedure instructions specific to your case. Following their recommendations diligently will help ensure a successful and effective colonoscopy experience.


Now, you may be thinking: what can I eat after a colonoscopy?

This timeline is very variable from person to person. Some may be able to go back to their typical diet directly after the colonoscopy. While others may still follow a low residue diet. Ask your doctor what is best for you.

After a colonoscopy, it’s recommended to slowly reintroduce foods into your diet to allow your digestive system to recover gradually.

Here are some general guidelines on what you can eat after a colonoscopy:

  1. Clear Liquids: Initially, start with clear liquids such as water, broth, clear juices, and tea. These liquids help to rehydrate your body and provide essential fluids without putting strain on your digestive system.
  2. Soft Foods: As your tolerance improves, you can transition to soft, easy-to-digest foods such as mashed potatoes, cooked vegetables without skins or seeds, smoothies, yogurt, pudding, and oatmeal. Avoid spicy, greasy, or heavily seasoned foods during this phase.
  3. Lean Protein: Incorporate lean protein sources such as chicken, turkey, fish, tofu, and eggs into your meals. Choose baked, broiled, or grilled options rather than fried or fatty preparations.
  4. Low-Fiber Foods: While you may gradually reintroduce fiber into your diet, it’s essential to start with low-fiber options initially. This includes white bread, white rice, pasta, and well-cooked vegetables without skins.
  5. Avoid Irritants: Steer clear of foods that may irritate your digestive system, such as spicy foods, high-fat foods, caffeine, alcohol, and carbonated beverages, at least initially.
  6. Stay Hydrated: Continue to drink plenty of fluids to stay hydrated and support your body’s recovery process.

It’s crucial to listen to your body and progress your diet based on how you feel. If you experience any discomfort or digestive issues after reintroducing certain foods, consider eliminating them temporarily and reintroducing them later when your digestive system has had more time to heal.

Always follow any specific post-colonoscopy dietary instructions provided by your healthcare provider, as individual circumstances may vary. If you have any concerns or questions about your post-colonoscopy diet, don’t hesitate to consult with your healthcare provider or a registered dietitian for personalized guidance.

Foods to Include on a Low Residue Diet

So, what are low residue foods to eat before a colonoscopy?

Below are a few foods to include on a low residue diet for a colonoscopy. As always, check with your doctor before any significant dietary changes.

Lean Protein Sources

  • Meat
  • Poultry
  • Fish
  • Eggs

Refined Grains

  • White Bread
  • Pasta
  • White Rice

Cooked or Canned Fruits and Vegetables

  • Applesauce
  • Peeled Potatoes
  • Tender Cooked Carrots
  • Canned Fruit

Dairy Products

  • Low-Fat Milk
  • Yogurt
  • Cheese


  • Clear Juices
  • Water
  • Herbal Teas
  • Broth

Foods to Avoid on a Low Residue Diet

Next, foods to avoid on a low residue diet for colonoscopy prep.

High Fiber Foods

  • Whole Grains
  • Nuts
  • Seeds
  • Legumes

Raw Fruits and Vegetables

  • Raw Salad Greens
  • Fresh Berries
  • Cruciferous Vegetables

Dairy Products

  • Full-Fat Milk
  • Cream
  • Ice Cream

Foods High in Gas

  • Carbonated Beverages
  • Beans
  • Cabbage

Sample Meal Plan for a Low Fiber Diet

Below is a one day sample meal for a low residue diet. It’s recommended to adjust to your preferences. Don’t be afraid to eat when you are hungry.

Breakfast: Scrambled Eggs with White Toast and Applesauce

Lunch: Chicken and Rice Soup with Cooked Carrots

Dinner: Baked Cod with Mashed Potatoes and Steamed Green Beans

Snacks: Yogurt, Rice Cakes, and Clear Juices

Tips for Successfully Following a Low Residue Diet for a Colonoscopy

  • Plan Meals Ahead of Time and Stock Up on Approved Foods
  • Stay Hydrated Throughout the Day
  • Monitor Symptoms and Adjust Diet as Needed
  • Seek Guidance from a Registered Dietitian or Healthcare Provider

Common Questions

Below are common questions regarding a low residue diet for a colonoscopy.

Are Scrambled Eggs Low Residue?

Yes, scrambled eggs are part of a low residue diet.

Can I Eat Mashed Potatoes Before a Colonoscopy?

Yes, mashed potatoes can be added to a low residue diet plan for a colonoscopy.

What Foods Can you Eat 3 Days Before a Colonoscopy?

As stated above, many doctors recommend following a low fiber or low residue diet 3-5 days before a colonoscopy.

This includes: lean protein, canned and cooked fruits and vegetables, low fat dairy, and fluids.

Foods to avoid: gassy foods, high fiber foods, raw fruits and vegetables, and full fat dairy.

When to Start a Low Fiber Diet Before a Colonoscopy?

First, it is essential to follow doctors orders as every person’s situation is different. They generally recommend starting a low fiber/low residue diet 3-5 days prior to the procedure.

Sometimes, the doctor will place you on a clear liquid diet the day before. Check out my article: Liquid Diet for Cancer Patients for a deep dive into a Liquid Diet.

Many doctors will recommend NPO or nothing by mouth the morning of the procedure. Some will allow clear liquids. Its essential to follow their directions.

What are Low Residue Foods for a Colonoscopy?

A handful of examples of low residue foods prior to a colonoscopy:

  • Apple Juice
  • White Grape Juice
  • Lemon Italian Ice
  • Orange Gealtin
  • Pudding
  • Chicken
  • Eggs
  • Canned Peaches
  • White Pasta

What is Considered a Light Meal Before a Colonoscopy?

Doctors may recommend not eating the day of the colonoscopy. Check with your provider prior to consuming intake.

Generally, a clear liquid diet is safe for the day prior to procedure. This can include clear juices, broths, Italian ices, and hot tea.


I hope this was helpful information for a low residue diet for a colonoscopy.

Best of luck on your journey.

If you’re interested in making overall diet adjustments, check out my Weekly Meal Planner to start organizing your meals!

Other Posts you may Enjoy:

Low residue diet for colonoscopy 1 day meal plan: Breakfast: Scrambled Eggs with White Toast and Applesauce 
Lunch: Chicken and Rice Soup with Cooked Carrots 
Dinner: Baked Cod with Mashed Potatoes and Steamed Green Beans 
Snacks: Yogurt,  Rice Cakes, Clear Juices

Portions of this article were auto generated using GPT-3 by Open AI. Upon generating draft language, the article was reviewed and edited accordingly. ProstateCancerNutrition.com takes ultimate responsibility for the content of this publication.

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