Small Intestinal Bacterial Overgrowth (SIBO)

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Small intestinal bacterial overgrowth (SIBO) occurs when bacteria — normally confined to the colon — colonize the small intestine in abnormally large numbers. These bacteria ferment carbohydrates that would normally be absorbed, producing hydrogen and/or methane gas and causing a characteristic constellation of symptoms. SIBO is increasingly recognized as an underlying cause of IBS-like symptoms that may have been previously dismissed or inadequately treated.

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Symptoms of SIBO​​

• Abdominal bloating and distension — often severe and worsening throughout the day

• Excessive gas and belching

• Diarrhea (hydrogen-predominant SIBO) or constipation (methane-predominant SIBO)

• Abdominal pain or cramping

• Fatigue and brain fog

• Nutritional deficiencies — vitamin B12, fat-soluble vitamins

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What Causes SIBO?

 

SIBO is associated with conditions that impair normal small bowel motility or structure: prior abdominal surgery (especially gastric bypass), hypothyroidism, diabetes, adhesions, strictures from Crohn's disease, and use of proton pump inhibitors. The migrating motor complex (MMC) — the 'housekeeping' wave that sweeps the small intestine clean between meals — is often impaired in SIBO patients.

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Diagnosis and Treatment​​​​

 

Diagnosis is confirmed with a hydrogen/methane breath test (see our SIBO Breath Test page). Treatment involves a course of rifaximin — a minimally absorbed, gut-specific antibiotic with an excellent safety profile. Patients with methane-predominant SIBO may require rifaximin plus neomycin. Dietary modifications (low-FODMAP, elemental diet in refractory cases) and treatment of the underlying predisposing condition help reduce recurrence.

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Book a SIBO Evaluation in NJ — Call (908) 851-2770 or Schedule Online