VA Ambulatory Report 12.13.17 – Flatulence!

Thanks to Vaibhav who presented his patient’s case of bothersome flatulence found to have positive celiac serologies, but negative EGD now being treated for H. Pylori.  This case allowed us to have an excellent discussion about approaching a less common chief complaint such as flatulence and how we diagnose celiac disease and IBS.

Learning Pearls    Screen Shot 2017-10-11 at 12.58.11 PM

  • Patients may experience belching (also called eructation), flatulence, or abdominal bloating due to decreased intestinal motility or increased sensitivity to normal gas production.  Reference the Rome IV criteria for diagnostic criteria of functional gastrointestinal disorders.
  • Healthy individuals are not able to completely digest some carbohydrates which leads to increased H2 production.  This is the basis for the H2 breath test for carbohydrate malabsorption
  • A low FODMAPs diet has good evidence for symptom reduction in patients with IBS. Some studies have shown benefit in other functional gastrointestinal disorders and in patients with IBD with symptoms such as bloating not explained by their inflammatory disease
  • Anti-TTG is testing for IgA antibodies and may be falsely negative in individuals with IgA deficency.  Consider co-testing with IgA levels or testing for Gliaden.  No test is perfect and the gold standard is small bowel biopsy.


More than you want to know about Intestinal gas

  • There is about 200 mL of gas in the intestinal system
  • The main elements in gas are nitrogen, oxygen, carbon dioxide, hydrogen, and methane
  • The odor in gas comes from minor elements such as methanethiol, dimethyl sulfide, hydrogen sulfide, short-chain fatty acids, skatoles, indoles, volatile amines, and ammonia.
  • Where does intestinal gas come from?
    • 1 – Swallowed air
    • 2 – Digestion of fat and protein leads to production of CO2 in the small bowel
    • 3 – Bacterial fermentation leads to production of Hydrogen and Methane
      • Hydrogen
        • Normal in the colon
        • Produced in the small bowel in SIBO
      • Methane
    • 4 – Carbohydrate malabsorption
      • In healthy individuals, foods with high concentrations of oligosaccharides (such as wheat, oats, potatoes, and corn, legumes) cannot be completely digested by enzymes within the normal small bowel, leading to increased H2 production
        • This increased colonic H2 production from carbohydrate ingestion is why we perform the H2 breath test for carbohydrate malabsorption
      • Fructose malabsorption may be an underappreciated cause of gastrointestinal symptoms. Up to one-half of the population cannot completely absorb the load of fructose consumed in the average diet
    • 5 – Diffusion from the blood
  • Gas Disorders (Look to the Rome IV criteria for diagnosing these conditions)
    • Belching (also called Eructition)
      • Involuntary belching occurs after meals
      • Can be increased by foods that decrease LES tone such as chocolate, fats, mints
      • Chronic, repetitive belching due to habitual air swallowing
    • Flatulence
      • May patients reporting bothersome flatulence produce a normal amount of gas but may be experiencing symptoms from it due to: alteration in intestinal motility or bacteria, dietary factors, or physiologic factors that heighten awareness of gas
    • Functional Abdominal Bloating and Distention
      • Correlation between symptoms of bloating and amount of gas production is inconsiente
      • Similar underlying contributors as flatulence: decreased gut motility, increased sensitivity to gas,
      • Rome IV criteria for diagnosis: recurrent bloating or distention at least on day/week and insufficient criteria for diagnosis of IBS, functional constipation, functional diarrhea, or postprandial distress syndrome


What is up with the FODMAPs diet?

  • FODMAPs = Fermentable, Oligo, Di, Monosaccharides and polyols
  • Studies have consistently shown improvement in symptoms on a low FODMAPs diet for patients with IBS including this recent RCT conducted in the US demonstrated a low FODMAP diet reduced IBS symptoms reduced symptoms
    • There is evidence it can be helpful in symptom reduction for other functional gastrointestinal disorders and in patients with IBD but symptoms such as bloating or discomfort that are not related to inflammatory disease
    • There is some evidence
  • Key concepts to teach to your patients
    • Elimination or limiting of all FODMAPs (not just one component)
    • FODMAPs foods are not the cause of the symptoms, but help reduce symptoms related to visceral hypersensitivity or decreased gut motility
  • Here is an excellent review article on FODMAPs


Diagnosing Celiac disease – why are Celiac Serologies so confusing?

  • When we check anti-TTG this is traditionally testing for IgA antibodies
  • Given the co-occurence with IgA deficiency, you may also want to test for IgA to ensure there is also not IgA deficiency leading to a false negative TTG
  • Gliaden is an IgG test and therefore avoids the problem with IgA testing
  • Gold standard is duodenal biopsy looking for
  • HLA testing is helpful in very specific instances (possibly in high probability population and discordance on serology and biopsy)
  • Remember, patients should be on a gluten-rich diet (yum!) when these tests are performed


What are the recommendations for “screening labs”

  • HIV: Screen in adults age 15-65 or at other ages if increased risk or pregnant
  • Screening for diabetes: USPSTF recommends screening in adults age 40-75 who are obese or overweight
  • Lipids: USPSTF recommends calculating ASCVD risk in all people 40-75
  • HBV, HCV: Screen in high risk individuals
  • No recommendations to get screening CBC, metabolic panel, or UA

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