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Lately there seems to be an epidemic of SIBO. SIBO stands for Small Intestine Bacterial Overgrowth. It is when “bad” bacteria populate your small bowel and cause gas and bloating every time you eat! It can cause painful gas, bloating, nausea, belching and other systemic symptoms. As the cartoon pictures shows, people with SIBO feel bloated ALL THE TIME and just feel “yucky.” Some people also have systemic symptoms like brain fog, fatigue, joint pains, and abnormal bowel habits (constipation or diarrhea). SIBO can even cause malnutrition because the “bad bacteria” are using all the nutrients from the diet! It is classically associated with low B12 levels.  Sometimes, SIBO can be “silent” without the obvious bloating symptoms, but cause other systemic symptoms such as fatigue, joint pains, brain fog, or insomnia.

SIBO was discovered by Dr. Mark Pimental, gastroenterologist at Cedars Sinai in 2006. It is now known to be an underlying ROOT cause of Irritable Bowel Syndrome (IBS). SIBO can also lead to more food sensitivities and intolerances.  Patients with SIBO can feel very limited in their food choices.

Why do people get SIBO? It can be caused by antibiotics, acid-suppressive medications, surgeries, chronic constipation, stress, and poor diet. Good news is SIBO can be definitively diagnosed by a Lactulose Breath test (see sample report above). This is a test where you drink a solution of lactulose (a non-absorbable sugar) and then collect your breath at 20 minute intervals. If you have SIBO, the “bad” bacteria in the small bowel will break down the lactulose and produce the Hydrogen (H2) and/or Methane (CH4)! Interestingly, the H2 predominant SIBO is associated with diarrhea while the CH4 predominant SIBO is associated with constipation.


If you think you may have SIBO, definitely ask about this test as we are seeing tremendous success in diagnosing SIBO. Great news is once you have a definitive diagnosis of SIBO, I can help you treat this condition. We are seeing great outcomes using a combination approach involving dietary changes, SIBO-specific antibiotics, or herbal antimicrobials.  Once SIBO is cleared, people feel significant relief and are able to eat many foods they previously could not tolerate! Bowel habits also normalize and the bloating is history.  Energy levels also improve significantly as your absorption of nutrients improves!

SIBO treatment involves 3 parts:

1) Killing the bacteria — antibiotics or herbal antimicrobials

2) Starving the bacteria — special SIBO diet (or sometimes an elemental diet)

3) Promoting motility

Having treated countless SIBO patients over the past few years, I have developed comprehensive protocols for treating hydrogen, methane, and combination SIBOs.   Most patients know they are better when their symptoms resolve and their bowel habits normalize.  Many patients choose to repeat the breath test after treatment, and it’s always a celebratory occasion when we see the “flat line” result indicating SIBO is gone!

Cheers to conquering SIBO!


Rajsree Nambudripad, MD



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