GI Conditions
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      2. GI Conditions

      Small Intestinal Bacterial Overgrowth

      Brief Overview: Small intestinal bacterial overgrowth (SIBO) is a condition that results when there is an excessive overgrowth of bacteria in the small intestine that leads to gastrointestinal symptoms. The most common symptom reported is bloating.

      Prevalence: The exact prevalence of SIBO is unknown.

      Etiology: SIBO has many causes and underlying conditions. Conditions that alter the balance of bacteria in the small intestine, or the movement of products through the small intestine, can lead to SIBO. Generally, the etiology of SIBO is divided into 5 categories: functional and motility disorders, anatomic disorders, immune disorders, gastric hypochlorhydria, and systemic disorders.

      Risk Factors: There are many risk factors for SIBO, including the many underlying conditions that can lead to the development of SIBO. Some of these include, but are not limited to:

      • Immunodeficiency (ex: HIV, IgA deficiency)
      • Long-term PPI use
      • Celiac disease
      • IBS
      • Diabetes
      • Hypothyroidism
      • IBD
      • Blind intestinal loops
      • History of gastric bypass, adhesions from previous surgery
      • Narcotic use
      • Scleroderma

      Commonly Associated Conditions:

      • IBS
      • Functional dyspepsia
      • Chronic pancreatitis
      • Chronic liver disease
      • Celiac disease
      • IBS
      • Intestinal failure

      Common Medications:

      • Antibiotics – rifaximin
      • Vitamin/nutrient supplementation as needed

      Common Labs, Imaging, and Tests:

      • Carbohydrate breath test
      • Lab tests may be performed in specific circumstances (CBC, celiac serologies, vitamin levels, etc.)
      • Stool tests may be indicated
      • Endoscopy, colonoscopy, small bowel biopsy may be performed

      Common Symptoms:

      • Bloating
      • Gas
      • Abdominal discomfort
      • Bowel changes – diarrhea, constipation

      Common Treatments:

      • Antibiotics – rifaximin
      • Vitamin/nutrient supplementation as needed
      • Treatment of any underlying cause

      Physical Findings:

      • Typically, normal physical exam
      • Abdominal distention may be present

      Potential Complications and Contraindications:

      • Malabsorption
      • Vitamin and nutrient deficiencies
      • Persistent symptoms, or recurrence
      • Progression or complication of chronic liver disease
      • Risk factors for recurrence: short bowel syndrome, jejunal diverticulosis

      General Health and Lifestyle Guidance:

      • Discuss with your healthcare provider and/or dietician if you should reduce/avoid fermentable products in your diet (kombucha, kimchi, sauerkraut, kefir, pickles, olives, sourdough, miso, wine, beer, cider, etc.)
      • Work with your healthcare provider to treat/manage any underlying conditions
      • Routine exercise (if approved by your healthcare provider) can help with gut motility

      Suggested Questions to Ask Patients:

      • Do you experience excessive bloating or gas, especially after eating?
      • Have you had any unexplained weight loss or fatigue?
      • Do certain foods worsen your symptoms?
      • Have you been diagnosed with IBS, celiac disease, or had abdominal surgery?
      • Have you taken PPIs or antibiotics long-term?

       

      Suggested Talking Points:

      • SIBO is generally treatable, but some people will have persistent symptoms or recurrence
      • The research and advice on probiotic use is mixed. Talk with your healthcare provider before initiating any probiotic therapy.
      • Make sure to report any new, worsening, or persistent symptoms to your healthcare provider.

      Sources: