Natural Health and Wellness for the Whole Family

SIBO: A Common Cause of IBS

By Sarah Axtell, ND January 21, 2014

IBS is the most common gastrointestinal disorder in the US. In fact, 15% of the population has IBS. IBS is a disorder characterized by abdominal pain, change in bowel function (constipation and.or diarrhea), and bloating. Until recently, the “It’s all in your head approach” to IBS has prompted prescriptions for anti-depressants as a common treatment for IBS. We now know that Small Intestinal Bacterial Overgrowth (SIBO) is a common underlying cause of IBS. In a study published in the Digestive Diseases and Sciences, more than 1/3 of the 320 subjects with IBS were diagnosed with SIBO.

SIBO is an emerging diagnosis, meaning that many doctors have not even heard of the condition and treatment protocols are still in the developing stages. So what is this 4 letter word and how does it related to IBS.?

Unlike the large intestine, in a normal healthy small intestine, there should be little to no bacteria. When overgrowth in the small intestine occurs, IBS–like symptoms occur. The bacteria in the gut produce gas, which causes bloating, gas, belching, and possibly reflux. Bloating after a meal is by far the most common symptom.

Signs that SIBO may be causing your IBS symptoms (gas, bloating, diarrhea, constipation, abdominal pain):

  • You felt improvement in your GI symptoms after antibiotics
  • You feel worse from probiotics containing prebiotics (such as FOS)
  • Eating fiber increased your constipation
  • You have been diagnosed with celiac disease or gluten sensitivity and you have not improved as much as your would have liked on a gluten-free diet.
  • You developed chronic GI symptoms after taking opiates post-surgery.
  • Your IBS symptoms were brought on by the use of antacids.
  • You have chronically low Iron for no other apparent cause.

What causes SIBO?

The most common cause I see is diets high in sugars and grains. Bacteria feed on sugars and carbs, and their byproducts cause gas and bloating. An integral part of treatment is diet therapy, in which grains and sugars are eliminated.

Our gut relies upon nerves and muscles to move food through the small intestines to the colon. When this process is disrupted, food no longer travels at an effective, efficient rate and direction. Damage to the nerves of the gut, which is common in diabetes, results in bacteria in the small intestine.

Scarring and strictures from Crohn’s disease can also cause backup of bacteria in the wrong spot (small intestine). Remember, bacteria is good as along as it is int he right place- the colon!

Medications can also promote bacterial overgrowth, such as opiates and antacids.

Testing for SIBO

The gold standard is a breath test. The patient must breathe into multiple vials over a period of a few hours. This will determine what gases were produced, which will then dictate treatment.

Common Recommendations for SIBO

  • Anti-microbials- Either Rx medications (such as Rifaxamin) or herbal antibiotics are effective at eradicating the small intestine of bacteria.
  • Diet- A diet low in carbs, grains, sugar and alcohol decreases the food source of the bacteria (and thus prevents the bacteria from reoccurring). The Specific Carbohydrate Diet and/or the FODMAPs diet are the ones I highly recommend for SIBO.
  • Allow 4-5 hours between meals. This allows for the migrating motor complex (or the cleaning-sweep of the intestines) to do its job in moving forward downward.
  • Prokinetic agents- these enhance gastrointestinal motility.

Suffer no more! Talk to your naturopathic doctor about whether or not SIBO may be playing a role in your gastrointestinal discomfort.

Editor’s Note: The information in this article is intended for your educational use only. Always seek the advice of your physician or other qualified health practitioners with any questions you may have regarding a medical condition and before undertaking any diet, supplement, fitness, or other health program.


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