Which statement about the frequency of primary versus secondary SIBO is true?

Which statement about the frequency of primary versus secondary SIBO is true?

• A. Primary SIBO is more common
• B. Primary and secondary SIBO are equally common
• C. Secondary SIBO is more common
• D. SIBO does not occur in the small intestine.

Answer: (C)

The key idea is that SIBO is usually driven by another problem that slows or alters small-intestinal flow, so bacteria end up overgrowing there. This makes secondary SIBO more common because many patients have an identifiable underlying condition—such as impaired gut motility from diabetes or connective-tissue diseases, structural changes after surgery, strictures or diverticula, or factors that reduce stomach acid or otherwise change the gut environment. Those issues are relatively prevalent in people with symptoms of SIBO, so the secondary form occurs more often in practice. Primary (idiopathic) SIBO, with no detectable cause, is less common. The statement that secondary SIBO is more common reflects what clinicians typically see. It’s not true that SIBO can’t occur in the small intestine.

The key idea is that SIBO is usually driven by another problem that slows or alters small-intestinal flow, so bacteria end up overgrowing there. This makes secondary SIBO more common because many patients have an identifiable underlying condition—such as impaired gut motility from diabetes or connective-tissue diseases, structural changes after surgery, strictures or diverticula, or factors that reduce stomach acid or otherwise change the gut environment. Those issues are relatively prevalent in people with symptoms of SIBO, so the secondary form occurs more often in practice. Primary (idiopathic) SIBO, with no detectable cause, is less common. The statement that secondary SIBO is more common reflects what clinicians typically see. It’s not true that SIBO can’t occur in the small intestine.