What is SIBO

Small intestinal bacterial overgrowth (SIBO) occurs when excessive bacteria accumulate in the small intestine, where bacterial levels should normally be low. This overgrowth interferes with digestion and nutrient absorption, leading to a range of uncomfortable symptoms.

Common SIBO Symptoms

The hallmark symptoms of SIBO include bloating (especially after meals), abdominal pain or cramping, excess gas, and changes in bowel habits such as diarrhea, constipation, or alternating between both. Other signs can include fatigue, brain fog, nausea, heartburn, and unintentional weight loss due to malabsorption of fats, carbohydrates, and key nutrients like B12 and iron.

Many people notice their belly becomes increasingly distended throughout the day as bacteria ferment undigested food, producing hydrogen or methane gas that stretches the intestines.

Why SIBO Often Looks Like IBS

SIBO and irritable bowel syndrome (IBS) share nearly identical symptoms—gas, bloating, pain, and irregular stools—which is why SIBO is sometimes called an "IBS mimic." Up to 60% of people diagnosed with IBS may actually have underlying SIBO. The key difference? SIBO is a measurable condition involving bacterial overgrowth, while IBS is a functional diagnosis based on symptom patterns without structural damage.

Different Types of SIBO

SIBO comes in different forms based on the dominant gas produced during bacterial fermentation, detected via breath testing:

Hydrogen-dominant SIBO: Linked to diarrhea-predominant symptoms, as hydrogen gas speeds up gut motility.

Methane-dominant SIBO (sometimes called IMO, intestinal methanogen overgrowth): Associated with constipation, since methane slows intestinal transit time.

Mixed or hydrogen sulfide SIBO: Can cause a combination of symptoms and may produce a rotten egg smell in stool or gas.

These distinctions guide targeted treatment, such as specific antibiotics, herbals, or prokinetics.

Next Steps for SIBO Concerns

If you're experiencing persistent bloating, pain, or bowel changes and wonder if SIBO is the root cause, breath testing can provide clarity. Schedule a 60-minute in-person or virtual / tele-health appointment (available to Alberta residents) to review your health history, symptoms, and whether testing is appropriate for you. We also offer free 15-minute discovery calls to discuss your concerns and create a personalized plan for digestive relief.