Small intestine bacterial overgrowth (SIBO) is a condition of the small intestine where abnormally large amounts of bacteria are present.  The small intestine (or small bowel) is the longest part of your digestive system and is made up of 3 sections – duodenum, jejunum and ileum.  The duodenum receives partially digested food from the stomach and this is where most of the chemical digestion of food takes place.  Both the jejunum and ileum function to continue digestion and move food into the large intestine.

Your small intestine should be nearly sterile.  However, when SIBO occurs your small intestine has large amounts of different types of bacteria that are typically found in the colon.  These different types of bacteria slow down the motility of your small intestine and can cause several digestive issues that I’ll discuss later.

I wrote about SIBO in my very first blog article on this website in January 2011.  At that time I was introducing it as a new premise for research on a drug that was developed to treat symptoms of IBS.  You can click here to view my original SIBO article.

SIBO – What are the Causes?

Doctors and scientists have thought for decades that the small bowel was a clean sterile environment.  Typically the small bowel receives food in a liquid state from the stomach and absorbs nutrients from it and then passes the indigestible food into the colon.  The colon then absorbs the water from the food and excretes the refuse in a more solid state.

However, when a trigger event occurs the normal function of the small bowel becomes compromised.  Something as simple as a reaction to antibiotics or a type of food you eat can trigger this change in the small bowel.  When this occurs your small bowel can take on harmful bacteria, which is the cause of SIBO.

SIBO – What are the Symptoms?

The symptoms SIBO presents are specific to the GI tract and abdomen area and they typically include:
•    Bloating and Gas
•    Abdominal discomfort/pain
•    Constipation
•    Diarrhea

Someone with SIBO will most likely have some of the symptoms listed above, but they do not need to have all of them.

SIBO – How is it Diagnosed?

The gold standard for diagnosing bacterial overgrowth is an invasive test where a sample is taken from the small bowel then cultured.  Because this is hard to do, a more common test is the Hydrogen Breath Test.  This involves drinking a substrate (sugar) and measuring hydrogen gas to see if bacteria are digesting this.  The problem with this test is that studies have shown that the test is not that reliable.  These studies have reported a wide range in the sensitivity and specificity of breath tests in diagnosing SIBO.

In my practice I choose to treat patients I suspect of having SIBO with an natural OTC product, and if they respond to treatment then we have made the diagnosis and treated at the same time.

SIBO – What Treatments are Available?

Treatment of SIBO consists of treatment of the underlying disease, dietary manipulation and antibiotic therapy. Even with all this, SIBO may be very difficult to get rid of.

Most often the first line of therapy is either with probiotics or antibiotics.   Probiotics have shown mixed results in studies and in some cases can even make the SIBO worse by adding more bacteria to the small bowel.   Antibiotics have shown the best data in studies, but there are limitations as well.  The most studied antibiotic is rifaximin, but only in diarrhea predominant IBS patients.  The major limitation is that it is very expensive and only around 10% better than placebo.  There are herbal antimicrobials as well, but they have not been studied as extensively, but case reports published do demonstrate significant improvement. Diet also plays a role by trying to “starve” the bacteria.   The FODMAP diet and an elemental diet both can accomplish this, but are hard to continue for a long time.

In my practice I have had the most success with a natural OTC product, which has been shown to eradicate the bacteria and improve symptoms even in patients who have failed the other regimens.

Disclaimer: The information presented on this website is not intended to take the place of your personal physician’s advice and is not intended to diagnose, treat, cure or prevent any disease.  Discuss this information with your healthcare provider to determine what is right for you.  All information is intended for your general knowledge only and is not a substitute for medical advice or treatment for specific medical condition