Doctor's Note

Check out these videos for more on diverticulosis:
More Than an Apple a Day: Combating Common Diseases
Uprooting the Leading Causes of Death
Say No to Drugs by Saying Yes to More Plants

And check out my other videos on fiber

For further context, also see my associated blog posts: Bowel Movements: the scoop on poopCholesterol Lowering in a Nut ShellOptimal Phytosterol Dose and Source; and Best Treatment for Constipation.

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  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos about fiber. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

  • grasshopper

    i’ve been a vegetarian, eating whole plant foods since the age of 21. i am lactose intolerant, but didn’t discover that till i was 18. at age 53, i was diagnosed with extensive diverticulosis and internal hemroids. i am confused as to why i have this condition after eating a plant-based high fibre diet for over 30 years, and have always had regular bowel movements? could the damage have occured in the first 20 years of my life? i soak and grind my nuts to ease digestion(food is undigested in the stool), and perhaps ease the bleeding of internal hemroids. Any ideas?

    • DrDons

      I would guess that either that the damage started earlier or for some reason you have a tendency to get diverticuli. Studies of populations who consume high fiber diets since birth show almost no diverticuli, appendicitis, and colon cancer. I believe that following a low fat whole plant based diet with B12 supplementation will be the best bet in avoiding problems in the future. Once some problems have developed and persisted despite us giving our bodies a chance to heal they sometimes need to be evaluated and fixed such as “banding” for internal hemorrhoids or we have to “learn to live with” problems that aren’t necessary to fix… it is often difficult to decide what to do. It is important for you to work with your physician(s) to make the best choice for yourself.

      • grasshopper

        thank you for your reply. i have tried banding 5 times to no avail. however, i’ve just been diagnosed with IBS. i suspect i am intolerant to all foods, but i suspect citric acid is a trigger that creates pain, and it is in my liquid B12 supplement. Can you recommend a B12 product without anything else?

        • DrDons

          I don’t have a B12 product that I can recommend. Sounds like you are still having GI problems. These can be incredibly difficult to sort out. You might be interested in the December 2002 newsletter article by Dr. John McDougall titled, The Diet for the Desperate. Go to his website and follow the link Newsletter Archives to get to December 2002 and then the article. Good luck.

          • grasshopper

            Thank you for the link to dr. mcDougall, this is a very clear elimination diet. i spent january on a 4 day rotation diet of botannical food groups, and strongly suspect that roasted nuts and seeds are problematic. in february i eliminated them from my diet and lost 10 pounds in 3 weeks. i’m 5’7″ and 113 pounds, too thin! i’m concerned about the lack of fat in my diet. do you know of other vegan choices for healthy fat and putting weight on?

          • AlexanderBerenyi


          • cheryl

            My sister used to be personal chief for Dr McDougal up in St Helena, Hospital, Angwin Calif….but we found the CHIP diet awesome. Many of the SDA churches are hosting Dr Hans Diehl of Loma Linda Med Centers, programs….is down right mind boggling what you learn…cooking classes, weeks of info!
            Its changed our lives!
            Check out
            think you can find it and where their programs being held…is worth every moment!

          • Chris

            I had some similar problems until I eliminated all dairy,meats,sugar,processed foods.Mainly eating fruits and salads and some beans,lentils,nuts.This only happened after doing a 7 day juice fast that gave my GI time to heal.I never have a problem since.Check out Dr.Robert Morse on youtube.There is more to learn about your body and why it’s rejecting foods.Try learning about lymph system.Sounds like you need a cleanse to be able to absorbe.This can be done by a mono fruit fast for minimal 3 day.Hope you achieve wellville.

          • 23123

            You’ve been eating whole food for 30 years yet are asking for advice about vegan fat sources?

            Gee, totally not a shill.

            I’ll kill you all.

          • cheryl

            Methyl B12 saved my life as I could absorb and convert the Cyano B12….
            I buy brand by Jarrow on line, but found Costco now carries it for very good price!
            I took 5K mcg every day and it cured my Peripheral Neuropathy within 8 weeks…
            this was documented by my having EMG and NC test up at OHSU med school then by Mayo Clinic!…it was only because I learned via BrainTalk communities web site, their studies about Methylcobalamin being a life saver and we MUST change the US lab standards to 600+ for B12 levels…mine was 232 and told was normal…but WHY did I have Neuropathy all over my body….and fatigue so bad I couldn’t raise my head off my pillow!
            but when I began taking Methylcobalamin B12, what your body uses after/or IF can absorb and convert into Methyl B12!
            These Harvard Neurologist at Brain Talk saved my life!…they really did!…no more fatigue, NO neuropathy!…thank God I had a laptop where I could at least do some research as to WHY I had Neuropathy, am non diabetic, was 54 yrs old then….but wow! My body couldn’t absorb and convert the regular, B12, aka Cyanocobalamin….now they’re learning that most people over 40 cannot do same!….check out what I’m writing here…may save your life as well!

          • cheryl

            serious typo error in beging….I left out I could NOT absorb and convert the usual Cyanocobalamin b12, and taking the Methylcobalamin B12 saved my life, almost overnite!

        • mauims

          I stopped taking B12 when Dr. G recommended RedStar nutritional yeast. I put 1 T in my morning shake.

      • So we might also be looking at the probiotic benefits of fiber. Any studies comparing breast fed vs formula populations?

    • AlexanderBerenyi

      A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis

      “Compared to individuals with 15 bower movements per week had a 70% greater risk for diverticulosis. Neither physical inactivity nor intake of fat or red meat was associated with diverticulosis.

      A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, prevalence of diverticulosis. Hypotheses regarding risk factors for asymptomatic diverticulosis should be reconsidered.”

    • Cindy

      DAIRY !?!

    • Patrick Ryan

      Maybe you weren’t getting enough probiotics and D3 if you’re in one of the northern States.. unfortunately they can’t be reversed so effective treatment is v important.. I know coz I have them too.. I keep mine at bay by making kefir which I mix with Resistant Starches like cold Basmati rice and raw grated potato.. this survives transit through the gastro-intestinal system until it reaches the colon where it is converted into butyrate, the colon’s preferred fuel and cure-all.. I also soak some dried figs and add these to the mix along with the liquor to make it more palatable.. I also stay on a low-carb diet and avoid sulfur containing foods like eggs and cruciferous vegetables which can degrade the protective layer of mucous in the colon thus leading to inflammation.. hope this helps.. BTW, sub-lingual B12 goes directly into your blood stream…

  • chewy

    is air popped popcorn ok to eat daily?

    • Michael Greger M.D.

      One of my favorite snacks! I like to sprinkle nutritional yeast on mine. What’s everyone’s favorite topping?

      • chewy

        so dr.greger, are plain brown rice cakes and plain puffed whole grain brown rice cereal ok to eat?not harmful foods despite the glycemic index….

      • Thea

        re: “What’s everyone’s favorite topping?”

        I too like nutritional yeast, but it doesn’t stick to the popcorn by itself. How do you really eat it/get the powder to stick?

        I tried spraying water on the popcorn and the putting the nutritional yeast on, but this only gave marginal success in getting the nut yeast to stick and the water wasn’t very appetizing on the popcorn. (I did try a fine-mist sprayer, but it didn’t really work.)

        Then, a few weeks ago I was watching videos on the PCRM 21 Day Kickstart program for India. The cook from India was doing a demo and had made some cashew paste as part of the recipe. The cook said that she thought that the cashew paste smelled like ghee, which is clarified butter.

        This gave me the idea of trying it on my popcorn. So, I put some cashews in the blender. Add just enough water to make a few of the top cashews float. Then I add a TON of nutritional yeast and bit of salt. Blend on turbo-high until it is very creamy. Add more water as needed to adjust for consistency and then poor over the popcorn.

        The result is *very* tasty, though it is important to make two notes: 1) it doesn’t really taste or spread like butter. 2) while this video and others show that whole nuts are generally good for you, adding nuts does add a fair number of calories. This topping means that you no longer have a low-calorie snack. But for a nice treat, perhaps while watching a special movie, this idea is a great substitute for traditional popcorn.

        For variations: I sometimes sprinkle on top various flavors of spices. MS Dash kind of thing. Or try just powdered garlic and onion on top. It will stick pretty good after pouring on the above concoction.

      • Alexandra Georgiadis


      • daisy

        i love my air popped popcorn plain! 
        i read your recipe for zombie popcorn,. do you  eat it often?is it fine  to eat a bowl of plain air popped popcorn everyday?the rest of my rather strict diet is based on leafy greens,other non-starchy veg,legumes and 2 pieces of fruit. i like simplicity!org air popped popcorn makes a great starch for me!fast,cheap and portable.just want to have reassurance that it is ok for the digestive tract to eat daily.

      • Patrick Ryan

        Loads of melted Kerrygold butter and pink Himalayan salt ^_^

  • DrDons

    Hi Chewy, Pop corn is an excellent food. Air popped is the best, much better than the traditional approach to popping it in oil. Processed oils are high in caloric density and hence calories but contain saturated fats as well.

    • Toxins

      Whats your take on non gmo corn? I have heard from non credible sources that non gmo corn, which has infested the corn supply, is a contributor to gluten allergies.

      • DrDons

        Hi Toxins,
        My take is that non GMO corn is better than GMO corn. Beyond that I’m not very knowledgeable about corn vs gluten.

  • chewy

    thanks dr dons!are plain brown unsalted rice cakes(lundberg) and nature’s path plain organic puffed rice healthy options too?

  • DrDons

    Hi Chewy, Rice cakes and cereal are good food choices but they are processed. Whenever foods are processed they usually have had fiber and nutrients removed, the complex carbohydrates have been modified for faster absorption… hence the higher glycemic index, and chemicals have often been added… just check the labels. Sometimes even the most benign sounding ingredients can have unintended consequences see two chemicals that can form benzene in sodas for instance. You can check out video So the foods that you mention are alot healthier than some options but they are not as healthy as others… a nutrient rich whole food plant based diet.

    • Susandison

      thanks for your reply dr. dons! can you explain why air popped popcorn is unprocessed yet puffed 100%whole grain brown rice is considered processed?

      • daisy

        could eating puffed rice and air popped popcorn ever cause colon polyps etc.?

  • chewy

    is air popped organic popcorn in any way harmful to the colon if eaten daily(which i do)

    • Toxins

       Air popped popcorn is by all means healthy! It is one of my favorite snacks and I would consume it everyday if i didn’t run out of kernels so often.

  • DrDons

    Of course you can overdo anything. In moderation I see no problem. The best diet is a whole plant based diet with a variety of foods.

  • Michael Greger M.D.

    Also be sure to check out my associated blog post Bowel Movements: The Scoop on Poop!

  • stacy

    DrDons, Can u give an outline of exactly what “whole food plant based diet” means?  There are so many variations on what a “whole food plant based diet” is, from starch-based, fruit-based, veg-based… McDougall, Fuhrman, Ornish, etc.  It’s enough to make one’s head spin!
    Also, regarding popcorn, aren’t the Acrylamides produced dangerous?

    And, what is the consensus on nutritional yeast?  I’d love to see a video on the pros and cons of it (dysbiosis contributor? MSG? candida etc)

    Some other suggested videos:
    -raw sauerkraut (like the one from Rejuvenative foods)

    -Probiotics: do they really help with dysbiosis?

    -digestive enzymes: are they beneficial, especially for people on a vegan or raw diet, and for those with digestive issues?

    -Food combining:  fact or fiction?

    -Macronutrients:  What is the optimal ratio (McDougall’s 10% fat or Fuhrman’s higher fat, for instance)?

  • daisy

    are air popped popcorn and puffed 100%whole grain brown rice approximately equivalent in nutrition ?

  • daisy

    could eating plain unsalted whole grain brown rice cakes cause polyps if eaten as part of a strict low fat gluten-free vegan diet(furhman/mcdougall) eating lots of vegetables raw and steamed,beans,fruit?

  • AmyD

    Dr. Greger – I’m curious about the link between diverticulitis and high-fiber diets – the study here: suggests that the more fibre we have in our diets, the more likely we are to develop this disease – do you have any other data on this?

    • anonymous

      so is popcorn perfectly safe and fine to eat?no chance of getting diverticulosis?

      • Toxins

        Popcorn does not cause this condition, lack of fiber does, which popcorn has.

  • Diverticulosis can be congenital as well. It’s basically a hernia of the bowel wall.

  • Kate

    Hooray, a video online that does not have someone starring me in the eye, for 20 minutes – going on and on about an advertised product!!! I almost did not watch the video, but I am glad I did – because of the pictures and demonstrations of what can happen in diverticulosis. I like this person!

  • Chrissy

    How bad is GMO popcorn (as opposed to non-GMO)? The only thing that keeps me from using organic popcorn is that the organic has more calories – 170 per 1/4 cup for organic, compared to 120 per 1/4 cup for the organic. (What the heck?)
    And on that note, why do the listed calories often differ substantially for the same or very similar foods? Are calories listings generally pretty accurate, and how often are they verified? For instance, the calorie content listed for frozen spinach is all over the map – from 20/cup for some brands, to 30 or 40 calories/cup for others.

    • Toxins

      I am not sure where you got that figure from, as they should have the same amount of calories.

      The most reliable source is the USDA database here.

      • Chrissy

        Thanks. I got that figure from the nutrition info on the package. I’ve noticed that according to the packages, the calories vary pretty substantially, which doesn’t seem to make sense. That’s why I was hoping Dr. G would weigh in.

        • Toxins

          That is strange indeed.

    • mauims

      Fwiw, GMO corn is not usually popped; rather, itʻs processed into HFCS and cornmeal, thus (with GM soy) invading 90% of super-market non-organic processed foods.

  • dbbrendle

    This note is in regard to puffed rice cakes and their nutritional value. Biochemist Paul Stitt reported the results of a test done on puffed wheat in his book “Fighting the Food Giants.” Comparing lifespans of rats fed four different diets: whole grains, vitamin/mineral supplements, sugar, and puffed wheat, the conclusion was that the puffed cereal was not only nutritionally depleted, but toxic. Puffed grain undergoes 1500 pounds of pressure which in some way destroys or damages the nutrient structures. The same is true for all puffed cereal. Popcorn takes a reasonable amount of heat, in a normal process that can be done in anyone’s kitchen (doesn’t require a manufacturing plant with super technology). You may view his book online at and see chapter 2 for the study.

  • matt

    Hmmmmm I cant help but thinking there must be a piece of the puzzle missing in the causative factors of diverticulosis. When I look at the anatomical aspect of the lesions I cant se how low fiber alone as a cause. I am aware that if the stool is bulky with protruding edges it could stretch and become weak. But when you see the opening to the pocket smaller than the inside of the pocket. Is it the stretching and thinning and then as the stool moves down the lumen then relaxes creates the shape? In theroy this is what is probably taught. I know colon cells have a high turnover and try to maintain their integrity. What could be the other mechanisms involved to give it its shape and possible continuous erosion? could it be acidic environment? poor cellular repair? bacterial effects? as it is seen in low fiber diets therefore higher animal base diets and altered colonic bacteria or lack of other plant nutrients that build new cells effectively? and when you see the color is different in the affected area compared to the non affected area? To me it looks like a reverse of a polyp? you could say then polyps are caused by interstitial constipation? I would really like to see some studies to show the whole pathophysiology of this disease so as to find a reversal of the existing condition. I am not sold on lack of fiber alone as a cause.Sorry about the pickiness :P but being picky is how I get results when treating my patients Any thoughts Dr Greger?

    • Toxins

      The shape of the lesions is not due to the shape of the stool. When you consume a low fiber diet, you have to push really hard to get the stool out of your body. This chronic constipation and chronic intense pushing of stools will lead to the protrusions within the lower part of the colon.

      It takes chronic constipation to reach the point of diverticulitis. Here is more information on stools.

      • mauims

        I seem to have developed “ileocecal valve syndrome.” At least, that is the only diagnosis I have received (from a holistic chiropractor/kinesiologist, after my two MDs and my mainstream chiro were stumped). The symptoms are aching pain, soreness and tingling in my right leg.

        This is my second episode. The first time, I was told to eliminate popcorn permanently and chocolate for ten days, which I did. This time, I am to avoid all hard, raw produce! This is very difficult, as I usually eat raw (although I drink my breakfast protein shake and juice my greens for lunch).

        Iʻve been vegetarian since ʻ74 and 99% vegan since ʻ92. Help!

    • Brenda

      My friend has been having a problem with her digestive system. She used to be over 300 pounds and has been dieting. When she is eating alone, she tends to not cook but snack on crackers and cheerios, sweets, etc. All of a sudden, she started throwing up and having diarrhea. Now she has hemorrhoids and is afraid to eat anything. I told her to eat baby food so she could get her nutrients and not have too much to digest. It has been working for her. They have not diagnosed her with anything particular but say the baby food diet is good if it is working for her.

  • Christie

    I had raw food/veggie allergies growing up and now in my adulthood I have this disease now.

  • cheryl

    I’m puzzled here…if on autopsy, seeds, corn and nuts are found in these diverticuli…aren’t other food items likely get stuck, not just the foods told us are the problem….aren’t these foods supposed to be mostly digested by time they’re that far down along intestines?
    I have Crohns disease, saw an allergist who suggested my negative reactions/sensitivities to many foods, are caused by my having celiac Sprue in spite of numerous biopsies/testing says I don’t have C-sprue.
    I’m so confused and am SICK and tired of vomiting whenever I swallow something my body doesn’t like…my biggie is Corn syrup…I projective vomit moments after swallowing it.
    Like last week…I love Pnut butter in small cup of applesauce…recently couldn’t find my usual, got an unfamiliar brand…didn’t think twice about it…began eating it during a meeting…I was starving and has always been a great food source…but 1 bite of this made me sick within moments…thank God I was able to make it out the door to vomit…but was a rather noisy event others could hear…I was totally embarrassed, but felt as if I would faint…I was shaky, dizzy, sweating profusely….
    My hubby looked at the food lable…you guessed it, High Fruitose corn syrup!
    is ridiculous…last night I made fruit soup….3 bites of it had me feeling very ill…the allergy dr told me I’m NOT allergic, just have a sensitivity to it and won’t need medical intervention such as Epin pen…but with my BP dropping, profuse sweating, vomiting each times, getting much worse, I’m wondering if this young dr is all that knowledgible…in the mean time…I MUST be more diligent in checking out lables on everything going into my mouth!
    I had recent bout of pneumonia…temp 104.7*…I also have Lupus and Fibromyalgia, so knew I best get to ER…was given antibiotics, sent home…I warned the dr that I’m allergic to corn syrup, not give me anything with it….so got home took the 2 teas cough syrup and immediately vomited it all back up…I spent an hour the next day trying to research the syrup ingrediants…but they do NOT list it
    I was too stupid enough to call the pharmacy…will do that now…duh!…but I trusted the ER dr to be diligent/smart enough to check out see if the recommended syrup had corn syrup base…can’t trust even an ER doc!
    what a mess I’m in….
    am looking at taking Probiotics…but some of those websites are a bit of a scam…use scare tactics during 1/2 presentation re our bodies having serious parasites…then they finally tell you its Candida…which they call a parasite after their long presentation…what they don’t tell you is that when you purchase even one bottle, you’re automatically signed up to receive on auto-ship….seriously…if they’re THAT wonderful, then WHY use lies, scare tactics during their childish artistic dry earaser pen/board presentation about how the government’s putting fats and sugars into our foods?!
    We’re trying hard to eat a plant based, vegan diet…we took a course called SDACHIP.ORG program…was very eye opening, mind boggling presentation b a Dr Hans Diehl from Loma Linda, Calif medical university hospital…is very hard diet to follow, but we’re determined to help our bodies as much as we can.
    thanks….Cheryl…Boring Oregon

  • Cynysha Thompson

    I am allergic to ALL tree nuts and I’m a Coeliac so I don’t eat popcorn. However, I don’t let this stop me from accessing the massive variety of produce that PROMOTE daily, proper bowel movements.

  • Liarsnnotallowed

    I have, via colonoscopy diverticulosis. I am 72, and I have been a vegan for two years, yet, I still get pain in the bowel. Any advice for keeping the diverticuli clean?

    • You have most likely been doing a good job for the last two years. The best thing you can do is stick with a whole food plant based diet. The higher fiber content will lower the risk of developing new diverticuli and keep the pressure in your colon lower to minimize problems with current diverticuli. Good luck and congratulations on moving to a healthier diet. Keep tuned as the science keeps changing.

  • Patrick Ryan

    Sulfur-Rich Foods can cause Ulcerative Colitis and so may play a part in causing diverticulosis also..

  • David Roberts

    Hi, my father has diverticulitis. His question is this, if he eats nuts or sweet corn, kiwi fruit, tomato….. these little grands or seeds will get stuck in the diverticulitis/pockets and cause inflammation and thus more bleeding. Is this true that the fibres will get stuck in the pockets? How does our body get rid of it in the stool? Thank you

    • Joseph Gonzales R.D.

      HI David. Did you see the end of the video? It seems totally fine to eat those whole foods, as more fiber in the diet might really help your dad.

  • judydcash

    I take a ‘saponifier’, an herbal drink called “Yuccan” which is a once a day tablespoon in water – it is great for ‘lubricating’ the stool, and helps prevent and slips the waste right out! I highly recommend it! see:

  • T

    I just came back from my colonoscopy, squeaky clean but have a mild diverticulosis in the sigmoid colon. I am not a vegetarian, eating very little meat, lots of veggies and some fruits and of course nuts and seeds, little bread, hardly any refined stuff and no sugar. I think this is pretty good isn’t it? So my doc says no nuts ands seeds and popcorn, exactly what the video presented “fiction”. I think I will continue what I eat, maybe crank my fiber up…