What is FD?

FD (recurring indigestion) is a relatively common and often frustrating condition. About one in six Americans have Functional Dyspepsia.1 FD is an under-diagnosed2 and under-managed condition. FD is a disorder of sensation and movement in the organs of the upper digestive tract where the normal downward pumping and squeezing is altered. The digestion and absorption of food nutrients can be affected.

What Causes FD?

In the absence of known organic cause, it is thought that FD is associated with the disruption in the lining of the gut (gut mucosal barrier) and reversible, localized, low-grade immune activation, which results in the impaired ability to digest and absorb food nutrients.3,4,5 Common triggers are food,6 stress,7 and environment.8 If FD is suspected, consult with a physician about confirming FD and then developing a program to manage it.


What Are The Symptoms of FD?

In addition to impacting the digestion and absorption of food nutrients, the symptoms of FD are in the upper belly and include, at varying times, some or all of the following:

  • Abdominal pain, discomfort, or cramping
  • Nausea
  • Burning
  • Bloating
  • Difficulty finishing a meal
  • Belching

Where do the Symptoms of FD Occur in the Digestive System?

FD occurs in the upper belly, above the navel. In FD, the stomach does not expand normally in response to a meal which means the food eaten backs up in the stomach and in the upper part of the small intestine.

Dietary Modifications

Physicians often recommend gradually increasing fiber intake, starting with 2-3 grams per day. Physicians may also recommend exclusionary diets such as excluding alcohol, caffeine, and high-fat foods. Also, NSAIDs are discouraged by physicians. Diet alone may not be practicable in managing FD, but should be part of your overall FD program, implemented with a physician.

Stress Management

Physicians may recommend common stress management tools including regular exercise, taking time to relax, and getting an adequate amount of sleep every night.


Unfortunately, no drugs are approved for FD. Physicians may either prescribe medications off-label or recommend over-the-counter products, to manage FD.


Physicians now increasingly recommend FDgard, a medical food specially formulated for the dietary management of FD. FDgard capsules contain individually triple-coated microspheres of caraway oil and l-Menthol, along with fiber and amino acids (from gelatin protein). Common triggers of FD are food,6 stress,7 and environment.8 That's why physicians are now recommending taking FDgard prior to a meal. FDgard has been shown in peer-reviewed presentations to be effective in managing FD symptoms.§,9


People with FD often do not eat regularly or normally, which may affect their normal intake of nutrients. Also, the digestion of food and absorption of nutrients is affected due to disturbances in the GI tract. For example, B12 and folate deficiencies have been observed in the FD population.10

There is increasing evidence that impaired mucosal defense mechanisms are implicated in the pathogenesis of functional gastrointestinal disorders (FGIDs), allowing inappropriate immune activation.11,12

More recently, perturbations of GI microbiota, altered mucosal permeability and abnormal mucosal defense mechanisms have been implicated in the pathogenesis of some FGIDs.13-18

Over 90% of nutrient digestion and absorption takes place in the small intestine.19 With FD, this digestive and absorptive process is disrupted in several ways. The bile acid flow is disrupted as part of the FD cascade of disruption.20 Peppermint oil (primary component: l-Menthol) helps restore secretory function such as bile flow.21 The German Commission E monograph for peppermint oil lists its use as an anti-spasmodic for bile ducts.22 This and other known activities of peppermint oil are helpful in digestion and absorption.


Dietary modification alone, as a management strategy, has had mixed success. Fiber is helpful. Exclusionary diets help in the short term but lead to nutritional imbalances and adherence issues in the long-term.23

Now doctors increasingly use medical foods, such as FDgard, to help normalize the digestion and absorption of food nutrients and to help manage FD symptoms.

FDgard is specifically formulated to meet the distinctive nutritional requirements of FD that cannot be met with dietary modification alone. FDgard is designed to supply microspheres of caraway oil and l-Menthol, which help enable proper digestion of food and enhanced absorption of nutrients and to help manage the symptoms of FD. By supporting gut health in the first place, FDgard helps prevent nutritional problems later.


The PreMeal Companion®


Talley, Nicholas J. 2017. “Functional Dyspepsia : Advances in Diagnosis and Therapy.” Gut and Liver 11 (3): 349–57.

2 Pleyer, C., H. Bittner, G. R. Locke, R. S. Choung, A. R. Zinsmeister, C. D. Schleck, L. M. Herrick, and N. J. Talley. 2014. “Overdiagnosis of Gastro-Esophageal Reflux Disease and Underdiagnosis of Functional Dyspepsia in a USA Community.” Neurogastroenterology and Motility 26 (8): 1163–71. doi:10.1111/nmo.12377.

3 Talley, NJ, MM Walker, and G Holtmann. 2016. “Functional Dyspepsia.” Curr Opin Gastroenterol 32 (4): 467–73. doi:10.1016/0300-2977(95)00099-9.

Stanghellini, Vincenzo, Francis K L Chan, William L. Hasler, Juan R. Malagelada, Hidekazu Suzuki, Jan Tack, and Nicholas J. Talley. 2016. “Gastroduodenal Disorders.” Gastroenterology 150 (6). Elsevier, Inc: 1380–92. doi:10.1053/j.gastro.2016.02.011.

Walker, Marjorie M., and Nicholas J. Talley. 2017. “The Role of Duodenal Inflammation in Functional Dyspepsia.” Journal of Clinical Gastroenterology 51 (1): 12–18. doi:10.1097/MCG.0000000000000740.

6 Feinle-Bisset, Christine, and Fernando Azpiroz. 2013. “Dietary and Lifestyle Factors in Functional Dyspepsia.” Nature Reviews Gastroenterology & Hepatology 10 (3). Nature Publishing Group: 150–57. doi:10.1038/nrgastro.2012.246

7 Aro, Pertti, Nicholas J. Talley, Jukka Ronkainen, Tom Storskrubb, Michael Vieth, Sven Erik Johansson, Elisabeth Bolling-Sternevald, and Lars Agréus. 2009. “Anxiety Is Associated With Uninvestigated and Functional Dyspepsia (Rome III Criteria) in a Swedish Population-Based Study.” Gastroenterology 137 (1). AGA Institute American Gastroenterological Association: 94–100. doi:10.1053/j.gastro.2009.03.039.

8 Wildner-Christensen, Mette, Jane Moller Hansen, and Ove B Schaffalitzky De Muckadell. 2006. “Risk Factors for Dyspepsia in a General Population: Non-Steroidal Anti-Inflammatory Drugs, Cigarette Smoking and Unemployment Are More Important than Helicobacter Pylori Infection.” Scandinavian Journal of Gastroenterology 41 (2): 149–54. doi:10.1080/00365520510024070

9 Thompson Coon, J, and E Ernst. 2002. “Systematic Review: Herbal Medicinal Products for Non-Ulcer Dyspepsia.” Alimentary Pharmacology & Therapeutics 16 (10): 1689–99. doi:10.1046/j.0269-2813.2002.01339.x.

10 Rasool, Shahid, Shahab Abid, Mohammad Perwaiz Iqbal, Naseema Mehboobali, Ghulam Haider, and Wasim Jafri. 2012. “Relationship between Vitamin B12, Folate and Homocysteine Levels and H. Pylori Infection in Patients with Functional Dyspepsia: A Cross-Section Study.” BMC Research Notes 5 (1): 206. doi:10.1186/1756-0500-5-206.

11 Bischoff, Stephan C, Giovanni Barbara, Wim Buurman, Theo Ockhuizen, Jörg-Dieter Schulzke, Matteo Serino, Herbert Tilg, Alastair Watson, and Jerry M Wells. 2014. “Intestinal Permeability – a New Target for Disease Prevention and Therapy.” BMC Gastroenterology 14 (1): 189. doi:10.1186/s12876-014-0189-7.

12 Kindt, S., A. Tertychnyy, G. De Hertogh, K. Geboes, and J. Tack. 2009. “Intestinal Immune Activation in Presumed Post-Infectious Functional Dyspepsia.” Neurogastroenterology and Motility 21 (8): 832–38. doi:10.1111/j.1365-2982.2009.01299.x

13 Kassinen A, Krogius-Kurikka L, Makivuokko H, et al., The fecal microbiota of irritable bowel syndrome patients differs significantly from that of healthy subject. Gastroenterology 2007; 133:24-33.

14 Annahazi A, Ferrier L, Bezirard V, et al. Luminal cysteine-proteases degrade colonic tight junction structure and are responsible for andominal pain in constipation-predominant IBS. Am J Gastroenterol 2013; 108:1322-31.

15 Lee H, Park JH, Park DI, et al. Mucosal mast cell count is associated with intestinal permeability in patients with diarrhea predominant irritable bowel syndrome. Neurogastroenterol Motil 2013; 19:244-50.

16 Matricon J, Meleine M, Gelot A, et al. Review article: associations between immune activation, intestinal permeability and the irritable bowel syndrome. Aliment Pharmacol Ther 2012; 36:1009-31.

17 Vanheel H, Vicario M, Vanuytsel T, et al. Impaired duodenal mucosal integrity and low-grade inflammation in functional dyspepsia. Gut 63 2014: 262-271; doi:10.1136/gutjnl-2012-303857.

18 Martinez C, Lobo B, Pigrau M, et al. Diarrhoea-predominant irritable bowel syndrome: an organic disorder with structural abnormalities in the jejunal epithelial barrier. Gut 2012; 62:1160-8.

19 Dr. Ananya Mandal, supra fn. 79.

20 Kamath, P.S. et al., abnormal gallbladder motility in irritable bowel syndrome: evidence for target-organ defect. Am J Physiol 260:G815-G819, 1991.

21 Zong, L. et al., Preliminary experimental research on the mechanism of liver  bile secretion stimulated by peppermint oil. J Dig Dis. 2011 Aug: 12(4):295-301.

22 Balakrishnan, A., Therapeutic uses of peppermint—A review. J Pharm Sci & Res. Vol. 7(7), 2015, 474-476.

23 Shepherd, Susan J., and Peter R. Gibson. 2006. Journal of the American Dietetic Association 106 (10): 1631–39. doi:10.1016/j.jada.2006.07.010.