5 reasons the low FODMAP diet might not be working for you.

Hello from sunny San Diego! I am so fortunate to be attending Digestive Disease Week, a yearly gastroenterology conference featuring state of the art research from around the globe regarding digestion and gastrointestinal disorders. If you are on twitter, follow the hashtag #DDW16 for real time tweets coming from the conference.  You can find me on twitter too: @KateScarlata_RD

I hope to post a little recap from the meeting in the next week or two!


Today’s topic is one that I have covered more or less in past posts…but I think, we can can benefit from some review.


The low FODMAP diet is an evidenced based diet therapy for individuals that suffer with irritable bowel syndrome. The research is variable, but it is estimated that about 70% of those who have IBS will benefit from the diet.  For those who have been suffering far too long with debilitating IBS symptoms, the low FODMAP diet provides a sense of hope and for many, a nutritional approach to feel better. Unfortunately, it doesn’t provide symptom relief for all who suffer with IBS. If you note only partial relief or no relief of your IBS symptoms after trying the low FODMAP diet, here are a few thoughts to consider.

You might be following the low FODMAP diet incorrectly!  Despite careful nutritional guidance, some FODMAPers inadvertently eat foods rich in FODMAPs. The biggest culprits in my practice include:

  • Gluten free foods with FODMAP ingredients such as: agave syrup, honey, chicory root extract, pear or apple concentrate.
  • Granola bars with chicory root extract, dates, or honey.
  • Coconut milk products with chicory root additives are also commonly found.

Here is more information about common pitfalls following the low FODMAP diet.

You might have small intestinal bacterial overgrowth (SIBO).  I find in my clinical practice, that the low FODMAP diet will offer only partial symptom relief for those who are suffering from SIBO. Most of my clients with the overlap of a SIBO diagnosis feel about 65-70% of their desired symptom goal on low FODMAP diet. When this occurs, I will send them back to the gastroenterologist for a SIBO breath test and suggest further work up for other conditions.

You are ridiculously constipated. If you don’t move your bowels regularly and experience a cleansing bowel movement, you likely will experience bloating, pressure in your intestines and pelvic area. Work with your gastroenterologist to find a suitable bowel regimen, consider being tested for methane + SIBO. Methane gas production in your gut is associated with constipation. I suggest you also discuss with your GI doc if he/she thinks you may be suffering from dyssynergic defecation. Dyssynergic defecation occurs when the muscles and nerves in your rectum don’t work properly to help you have a BM. This condition can be successfully treated with pelvic floor physical therapy (yes, it works) and/or biofeedback.

You are not FODMAP sensitive. 30% of IBS sufferers do not benefit from the low FODMAP diet. You may benefit from another dietary approach. Visit with a dietitian to explore other nutritional interventions based on your full symptom profile and medical history.  Rather than try to do all the detective work yourself, work with a forward thinking gastroenterologist and GI nutrition knowledgeable dietitian to explore other nutritional approaches based on your history.  For example, individuals with overlapping fibromyalgia, chronic bladder pain, chronic sinuses infections and/or allergy symptoms, might benefit from evaluation of mast cell activation syndrome. I have had a subset of clients with these conditions benefit from a low histamine diet and medication therapies directed toward stabilizing the mast cells. Mast cells release inflammatory chemicals and are more prevalent or perhaps more active in individuals with IBS.

You suffer from bile acid diarrhea (BAD), learn more about BAD here. This can occur if you make more bile than you need or it is dumped into your intestine too quickly.  We also see bile induced diarrhea in individuals that suffer with SIBO, as some microbes that can be present in your small intestine (they don’t belong there!) can render your bile inactive. Inactivated bile travels to the colon, pulls in water and encourage colonic motility.  The end result: diarrhea. Talk to your gastroenterologist about the possibility of this condition.

Enjoy the week ahead!

16 replies on “5 reasons the low FODMAP diet might not be working for you.

  • Megan King

    Thank you for this- your work is greatly beneficial for many!!
    Constipation is definitely a culprit. Do you know if taking MiraLax daily can exacerbate symptoms and make the low FODMAP diet feel less successful? Also, this is the first I have heard of the methane + SIBO topic. Do you have a post discussing this?

    • Jim

      The GastroLab breath testing regime here in Melbourne, Australia does an initial control test which will establish whether or not your gut produces hydrogen (most people) or converts the hydrogen to methane (~15odd% of population). That was me, & further google reading of some medical research indicated the constipation link. It fits my symptoms. Of course, the standard psyllium-based treatments were counter-productive. I then got RD advice to use sterculia-based (plant fibre extract) products, eg the Norgine brand Normacol (which are non-fermentable, compared to psyllium). Improved my circumstances a great deal.
      Interesting to see this now getting some attention. Last year I had my GP doctor taking notes.

  • Kara

    Hello! Great Info and I love the link to your past post! I needed that one! One problem that I am having is that I have been losing too much weight. I was diagnosed with fructose malabsorption last Aug and started this diet then and ever since have steadily lost weight. I haven’t been able to successfully reintroduce anything into my diet at all, with the exception of some cheeses and dairy. My system has been very sensitive! Your website and recipes have really been a lifesaver because at the beginning I had no idea where to start-so thank you very much! If there’s just some way to start adding some bulk to this little frame to replace that lovely gluten, I would truly appreciate it!

    • katescarlata

      First, be sure you don’t have bacterial overgrowth of the small intestine that can contribute to fat malabsorption, and probably a good reason you are super sensitive to FODMAPs. For calorie bulking ideas–I would be sure to include larger portions of low FODMAP foods such as white potatoes, rice, and fish, lean beef or poultry. Include a couple snacks per day to boost calories too. My favorite snack is the 88 Acres granola bars. So yummy and filling!

      • Kara

        Thanks! I will try all of that! I do already eat lots of potatoes and rice, but could get better at the snacking!

  • Pam Valois

    When traveling, may I use the lactose enzyme pills when using milk in cofee and cereal?
    Also, is coffee ok?
    Thank you

    • katescarlata

      Hi Pam–Coffee 1-2 cups is acceptable–though caffeine can speed up GI transit and can contribute to symptoms,in some people. As for using lactase supplements—as a general rule–that is okay—but initially–the first 2 weeks of the diet–I tend to recommend just using lactose free products to get a more clear picture if the diet is working. Then patients can trial the use of enzymes.

      • katescarlata

        Pam, I think Fritos should be okay…not sure about corn nuts. Corn can be produced with higher starch component (not FODMAPs) vs. short chain carbs–more likely FODMAPs (such as corn on the cob)

  • Linda M.

    Hi Kate,
    I have a doctor appointment with my gastro doctor in an hour. I am the person that lives in Southern Oregon where there is little, to no knowledge of The Low Fodmap diet, or even Sibo. I have printed off a copy of the information that you just provided to us. I too am still losing weight, and am so constipated that I am miserable. I believe that I have Sibo, but my breathe hydrogen test was only for one of the causes. I feel so over-whelmed; as my doctor said that going to a dietitian was not necessary. I am going to tell him today that it is needed, and if they are going to tell us to be on The Low Fodmap diet, then we need some guidance and directions. The only dietitian here is for diabetics, and they did not even no what Sibo, or Low Fodmap was. Thank you for all the information that you provide to us!

  • Thyra

    I’m wondering about sugar beet syrup.
    Do you know if it is low FODMAP, like common table sugar or possibly high like sugar beet fiber?
    Thanks for all your help!

  • Holly

    Thank you for all your wonderful tips and guidance! It’s so appreciated!
    May I ask, the Monash app it VERY helpful but I want to clarify something. For example, it says that we can have 10 strawberries, and then 1 medium banana. Can that be all together like in a smoothie? Or since mixing them, should the allowed amounts me cut back when combining them? I just like to make sure I don’t over do it. Also, caffeine intake. I know too much caffeine can trigger symptoms, but how much is that? I like iced tea, black and green. I don’t do black anymore as I read its high fodmap, and that green tea is safe. So is it safe to drink 20 or so ounces of iced tea, or should it be limited?
    Thanks for your help!!

  • Kelly

    Do you offer any classes for dietitians to improve their skills/understanding of digestive health issues? I am getting more referrals for IBS patients and the FODMAPS diet is not always working. I don’t have enough expertise to answer all of their questions and am struggling to find good resources.

    • katescarlata

      I offer dietitian coaching–and this has been going very well!! Many of the RDs I have coached have gone off to be quite successful in the world of FODMAPs. Call my office to schedule or learn more, 508-533-0800.

Comments are closed.