What vegetables can I eat 3 days before a colonoscopy?

When preparing for a colonoscopy, following a low fiber diet is crucial. This means avoiding vegetables, fruits, nuts, seeds, whole grains, and other high fiber foods during the days leading up to the procedure. Most doctors recommend sticking to a low fiber diet for 2-3 days beforehand. This allows time for the colon to empty out and clears the way for your doctor to view the colon walls most effectively.

Quick Answers

Here are quick answers to common questions about what vegetables you can eat before a colonoscopy:

  • Low fiber vegetables like carrots, green beans, eggplant, lettuce, potatoes without skin, zucchini, pumpkin, mushrooms, onions, tomatoes, cucumbers, asparagus tips, avocado, canned vegetables without skins/seeds, olives.
  • Avoid all raw vegetables. Cooked and canned vegetables are better tolerated.
  • Do not eat vegetables that are high in fiber like broccoli, cauliflower, corn, peas, brussel sprouts, artichokes, squash, beans, cabbage, celery, radish, onions, okra.
  • Remove all seeds, skin, and membranes from allowed vegetables since fiber is concentrated there.
  • Juices without pulp are okay.

How Many Days Before a Colonoscopy Should I Follow a Low Fiber Diet?

Most doctors recommend sticking to a low fiber diet for 2-3 days before a colonoscopy. Some may advise starting up to 5 days beforehand. Here are some general guidelines:

  • 5 days before: Start eliminating high fiber foods if you tend to have constipation. Gradually taper down fiber intake.
  • 3 days before: Follow a strict low fiber diet. Avoid all high fiber vegetables, fruits, whole grains.
  • 2 days before: Continue the low fiber diet. Drink only approved clear liquids.
  • 1 day before: Follow a completely liquid diet. No solid foods allowed.
  • Day of procedure: No eating or drinking 2-4 hours before your colonoscopy as instructed by your doctor.

Checking with your individual doctor about when to start the low fiber diet is recommended since guidelines can vary. Starting to restrict high fiber foods 5-7 days in advance is often suggested for those prone to constipation.

Why Follow a Low Fiber Diet Before a Colonoscopy?

Here’s why it’s so important to restrict fiber intake before a colonoscopy:

  • Clears the colon: A low fiber diet reduces waste moving through your colon. This cleansing helps ensure your doctor can view the colon walls fully.
  • Prevents clogs: Fiber residue can clog the scope camera during your procedure, blocking key areas from view.
  • Improves prep: Large undigested pieces of fiber can remain behind even after colonoscopy prep. A low fiber diet helps minimize this.
  • Reduces discomfort: Clearing out high fiber foods can make the bowel prep process feel more comfortable.

What Foods Should Be Avoided?

Here are the main types of high fiber foods to eliminate on a pre-colonoscopy diet:

  • Whole grains: brown rice, whole grain bread, whole grain pasta, quinoa, barley, oats.
  • Fruits: prunes, berries, pears, apples, oranges, grapefruit, raisins, apricots, figs, mangoes.
  • Vegetables: broccoli, peas, corn, brussel sprouts, artichokes, green beans, squash, celery, carrots, potatoes with skin.
  • Legumes: all beans, lentils, chickpeas, soybeans.
  • Nuts and seeds: flaxseed, chia seeds, almonds, walnuts, pistachios, peanuts.

Also avoid any other food specifically identified by your doctor as too high in fiber. Be sure to read all food labels carefully. And remember no raw fruits/vegetables which are harder to digest.

Low Fiber Vegetables for a Colonoscopy Diet

When keeping fiber low 2-3 days before a colonoscopy, these types of vegetables are usually allowed:

Vegetables Preparation Tips
Carrots Cook thoroughly, avoid raw. Remove skin/membranes.
Green beans Remove strings and ends. Can have canned.
Eggplant Peel off skin. Cook well until soft.
Lettuce Remove tough stems. Romaine and iceberg okay.
Potatoes Remove all skin. Bake, boil, mash thoroughly.
Zucchini Remove skin and seeds. Cook until soft.
Pumpkin Remove skin. Cook and mash/puree thoroughly.
Mushrooms Slice thinly. Sautee or boil to soften.
Onions Slice thinly. Avoid raw. Sautee or boil well.
Tomatoes Cook thoroughly. Remove seeds and membranes.
Cucumbers Remove skin and seeds. Slice thinly. Soften with cooking.
Asparagus tips Slice off tough ends. Chop tips finely.
Avocado Puree well to avoid chunks.

Some key tips when choosing allowable vegetables:

  • Cook thoroughly until very soft.
  • Puree or mash to avoid fiberous strings.
  • Remove all skins, seeds, stems which contain most fiber.
  • Canned and boiled vegetables can be better tolerated.

Sample Low Fiber Vegetable Meal Plan for Colonoscopy Prep

Here is a sample 1-day low fiber vegetable menu when prepping for a colonoscopy:


  • Poached eggs
  • White toast with butter
  • Low fiber cereal like corn flakes with milk
  • Coffee or tea with white sugar


  • Chicken breast
  • White rice
  • Green beans
  • Mashed potatoes
  • Vegetable juice without pulp


  • Roast turkey
  • White pasta
  • Well-cooked carrots
  • Canned mushrooms
  • Vegetable juice without pulp

Focus on low fiber options like:

  • Tender cooked vegetables without skin/seeds
  • White rice, plain pasta, crackers
  • Chicken, fish, eggs, turkey, tofu
  • Canned fruits/vegetables
  • Butter, oils, creamy sauces
  • Juices without pulp

Avoid high fiber foods like:

  • Whole grains
  • Raw veggies
  • Legumes
  • Nuts/seeds
  • Dried fruit
  • Popcorn
  • Chips
  • Bran cereals

Tips for Low Fiber Vegetables Before Colonoscopy

Here are some extra tips when choosing and preparing allowable vegetables on a pre-colonoscopy low fiber diet:

  • Go for tender, easily digested options: zucchini, potatoes, carrots, mushrooms, asparagus tips.
  • Cook thoroughly until extra soft: this helps break down tough cell walls.
  • Puree or mash: blend cooked veggies into a smooth puree or mash without lumps.
  • Dice finely: cut vegetables into tiny pieces to minimize fiber.
  • Remove all skins, seeds, stems: peel off vegetable skins which are high in fiber.
  • Steam or boil: cooking with water helps soften fiber strands.
  • Avoid raw vegetables: raw has higher fiber content. Cook thoroughly.
  • Canned vegetables can work: choose low salt and rinse before eating.

What About Juices Before Colonoscopy?

Drinking vegetable juice can provide needed vitamins and minerals when avoiding high fiber foods before a colonoscopy. Here are some tips on juices:

  • Choose 100% vegetable juices like V8, tomato, carrot juice.
  • No pulp: only have juices that have pulp removed.
  • Avoid juice blends with fruit or high fiber add-ins.
  • Limit to 1 small glass per day as juices still have natural sugars.
  • Avoid juice with skins, seeds, stalks blended in.
  • Homemade juice without pulp may be okay if strained well.

Juicing vegetables helps remove some of the fibrous content. But juices can still have residual fiber, so drink in moderation.

Are Potatoes Allowed?

Potatoes are one vegetable that can still be included in a low fiber diet for colonoscopy prep. Here are some tips on how to include potatoes:

  • Remove skin entirely: the highest amount of fiber is in the skin which must be peeled off.
  • Chop potatoes into small, uniform pieces before cooking to reduce fiber strands..
  • Boil or bake potatoes until extremely soft all the way through.
  • Mash or puree cooked potatoes with broth or oils to make a smooth creamed soup.

Potatoes with peeled skin, thoroughly cooked and mashed are gentle enough for the colon when prepping for a colonoscopy. Limit to 1 cup serving per day.

What About Salad and Lettuce?

Salads and lettuce often come to mind when thinking of low fiber foods. But there are some risks associated with eating them before a colonoscopy.

  • Using dressings and oils can cause diarrhea which you want to avoid.
  • Raw vegetables are harder to digest than cooked.
  • Fibrous strands in lettuce can cling to the colon.
  • Some veggies like cabbage have more fiber than lettuce.

If having salad or lettuce, choose green leaf or iceberg varieties which have the lowest fiber. Remove any tough stalks or stems and chop into small pieces. Pair it with an allowed low fiber dressing. Limit to 1 cup per day.

What About Onions and Garlic?

Onions and garlic can sometimes cause bloating or gas, so they may be avoided for a colonoscopy. But they don’t have to be eliminated entirely. Here are some tips for including them:

  • Prepare small amounts only to limit fiber intake.
  • Cut onions into thin slices and cook thoroughly until softened.
  • Crush/mince garlic before cooking to ease digestion.
  • Sautee onions and garlic in oil rather than eating raw.

Onions and garlic prepared this way are usually tolerated in small quantities. Evaluate your own tolerance levels. Stop eating them entirely if they cause discomfort.

Should I Avoid All Vegetables?

While a very low fiber diet is needed before a colonoscopy, you don’t necessarily have to avoid vegetables altogether. Here’s why some can be included:

  • Vegetables provide antioxidants, vitamins, and minerals.
  • Some vegetables are naturally lower in fiber like iceberg lettuce, cucumbers, zucchini.
  • Cooking and preparing vegetables thoroughly reduces fiber content.
  • Limiting portions lets you monitor fiber intake.
  • Avoiding all vegetables may lead to greater constipation.

The key is choosing the lowest fiber vegetables and preparing them appropriately. Still limit portions to 1/2 – 1 cup per day. Skip vegetables completely if you experience discomfort.

What About Avocados?

Avocados are unique because even though they are a fruit, they contain beneficial monounsaturated fats and fewer carbs. Here is how to incorporate avocados into a low fiber colonoscopy diet:

  • Choose ripe avocados which are lower in fiber.
  • Remove skin and pit which have more fiber.
  • Puree the flesh thoroughly to avoid chunks.
  • Combine with allowed oils for salad dressing or smoothies.

Pureed avocado adds creaminess and healthy fats without too much excess fiber. Limit to 2-3 tablespoons per day before colonoscopy.

Should Seeds and Skins Be Avoided?

Definitely avoid seeds and skins from fruits and vegetables when following a low fiber colonoscopy prep diet. Here’s why:

  • Seeds and skins contain the highest concentration of fiber.
  • They resist breakdown during digestion increasing fiber content.
  • Skins and seeds can clog up the colonoscope during your procedure.
  • They can cling to colon walls even after bowel prep.

For any allowed vegetables or fruits, always remove the skin, seeds, stems, and membranes before eating. This significantly reduces the fiber content.


When preparing for colonoscopy, restrict high fiber foods starting 2-3 days beforehand. Follow a strict low fiber diet with allowed foods like skinless potatoes, tender cooked low fiber vegetables, white breads, eggs, juice without pulp, chicken, and fish. Avoid all vegetables, fruits, and grains high in fiber. Scrutinize food labels to keep fiber grams very low. With the proper diet, you can help ensure the most effective colon cleansing before your colonoscopy procedure.

Leave a Comment