What Is SIBO?

If you feel bloated after nearly every meal—even healthy ones—you could be dealing with more than just indigestion. It might be SIBO, or Small Intestinal Bacterial Overgrowth, a condition where excess bacteria grows in the small intestine where it doesn’t belong.

These misplaced microbes ferment the food you eat, especially carbohydrates, leading to gas, bloating, diarrhea, constipation, and even nutritional deficiencies. SIBO is more common than people think—and often misdiagnosed.

Common Symptoms of SIBO

Wondering if you might have SIBO? Here are the most frequent signs:

  • Chronic bloating and abdominal discomfort
  • Gas and belching
  • Diarrhea, constipation, or alternating between both
  • Feeling full quickly or nausea after meals
  • Unexplained weight loss
  • Fatigue or “brain fog”
  • Vitamin or nutrient deficiencies (especially B12 and iron)

Sound familiar? These symptoms can mimic IBS, making SIBO tricky to spot without proper testing.

What Causes SIBO?

SIBO occurs when the natural balance of gut bacteria is disrupted and bacteria migrate or overgrow in the small intestine. Some of the most common causes include:

  • Slow gut motility (often due to diabetes, hypothyroidism, or surgery)
  • Structural problems in the GI tract (like strictures or adhesions)
  • Previous abdominal surgeries or scarring
  • Long-term use of acid-blocking medications (PPIs)
  • Chronic constipation or irritable bowel syndrome (IBS)

How Is SIBO Diagnosed?

SIBO is typically diagnosed through a breath test that measures hydrogen and methane gas levels after consuming a sugary solution like lactulose or glucose. These gases are byproducts of bacterial fermentation and can be detected when bacterial overgrowth is present.

Your gastroenterologist may also recommend additional blood work, stool tests, or imaging if other conditions are suspected.

The Real Dangers of Leaving SIBO Untreated

When left unchecked, SIBO can lead to serious complications, including:

  • Malabsorption of nutrients
  • Weight loss and muscle wasting
  • Increased food intolerances (like lactose or FODMAPs)
  • Leaky gut and systemic inflammation
  • Progression to chronic fatigue or autoimmune conditions

That’s why it’s crucial to get evaluated if symptoms persist—especially if standard diets and antacids aren’t helping.

How Is SIBO Treated?

Treatment typically involves a three-part approach: antibiotics or antimicrobials, diet modification, and prevention of recurrence.

1. Prescription Antibiotics

  • Rifaximin: A non-absorbed antibiotic that targets bacteria in the small intestine
  • Neomycin: Sometimes combined with rifaximin for methane-dominant SIBO

2. Herbal Antimicrobials

  • Alternatives for those who can’t tolerate antibiotics
  • Examples include oregano oil, berberine, and allicin (garlic extract)

3. Diet Adjustments

A low-FODMAP or SIBO-specific diet can reduce symptoms during treatment. These diets limit fermentable carbs that feed bacteria.

4. Address the Root Cause

To prevent relapse, underlying issues like slow gut motility, hypothyroidism, or structural abnormalities need to be treated or managed.

FAQs About SIBO

Can SIBO go away on its own?

It’s rare. Most cases require targeted treatment and long-term management to prevent recurrence.

How long does it take to treat SIBO?

Most treatments last 2 to 4 weeks, but some cases require multiple rounds or long-term care.

Is SIBO contagious?

No, SIBO is not spread from person to person. It’s related to internal gut dysfunction.

Can probiotics help SIBO?

Probiotics may help some, but they can worsen symptoms in others. Always consult your doctor before adding supplements.

What if symptoms return?

Relapse is common. Maintenance treatments and addressing root causes are key to long-term success.

Final Thoughts from Your Gastroenterologist

If you feel like you’re reacting to everything you eat—or if bloating, gas, and stomach pain are controlling your life—SIBO might be the hidden culprit. The good news? It’s treatable. Don’t guess. Get tested, treated, and supported with a personalized plan that gets to the root of your gut issues. Relief is possible—and it starts by taking that first step.