Small Intestinal Bacterial Overgrowth – SIBO
If you are living with persistent abdominal pain, chronic bloating, diarrhea, or constipation that has not responded to standard treatments, you may be experiencing Small Intestinal Bacterial Overgrowth (SIBO).
Understanding SIBO: Relief from Chronic Bloating, Gas, and Digestive Discomfort
This frequently overlooked condition affects millions of Americans. Because its symptoms mimic other digestive disorders, it is often misdiagnosed as standard Irritable Bowel Syndrome (IBS). Our board-certified gastroenterologists specialize in identifying and treating SIBO using evidence-based diagnostic testing and individualized care plans designed to restore your gut health and improve your quality of life.
What is SIBO?
SIBO occurs when bacteria that normally reside in the large intestine migrate upward and overpopulate the small intestine. Unlike the large intestine, the small intestine is meant to have a relatively low bacterial population.
When this balance is disrupted, these overgrown bacteria begin fermenting carbohydrates prematurely—before your body can properly digest them. This fermentation process produces an excess of hydrogen and/or methane gas, interfering with nutrient absorption and triggering a cascade of uncomfortable gastrointestinal symptoms.
Key Facts at a Glance:
SIBO affects an estimated 6% to 15% of healthy adults and up to 80% of individuals diagnosed with IBS.
It can cause malabsorption of critical nutrients, including iron, vitamin B12, and fat-soluble vitamins.
It is a recognized, fully diagnosable, and treatable medical condition.
Signs and Symptoms of SIBO
SIBO symptoms can range from mild discomfort to severely debilitating disruptions to your daily routine. They typically intensify after eating, particularly after consuming fiber or carbohydrates.
Gastrointestinal Symptoms
Abdominal bloating and visible distension (which often worsens as the day progresses)
Excessive gas and frequent belching
Abdominal pain and cramping
Chronic diarrhea, stubborn constipation, or alternating between both
Nausea or a feeling of fullness very quickly after starting a meal
Systemic Symptoms
Because SIBO affects nutrient absorption and triggers systemic pathways, it can cause symptoms outside the digestive tract, including:
Unexplained chronic fatigue and brain fog
Nutritional deficiencies (such as iron-deficiency anemia or low vitamin D)
Unintended weight loss or joint pain
Skin issues, such as rosacea or eczema, driven by gut-skin axis dysfunction
The Three Main Types of SIBO
Identifying the specific type of SIBO you have is essential, as the gas produced determines the most effective treatment approach:
Hydrogen-Dominant SIBO: The most common form, where bacteria produce excess hydrogen gas. This type is typically associated with chronic diarrhea and loose stools.
Methane-Dominant SIBO: Also known as IMO (Intestinal Methanogen Overgrowth), this is caused by an overgrowth of methane-producing organisms called archaea. It is most commonly associated with stubborn constipation.
Hydrogen Sulfide SIBO: A newer classification characterized by distinct, sulfurous gas, diarrhea, and significant abdominal discomfort.
Causes and Risk Factors
SIBO rarely develops on its own. It is almost always the result of an underlying health condition that disrupts normal intestinal motility (movement), alters internal anatomy, or lowers stomach acid. Identifying your specific risk factors is essential to preventing the condition from returning.
Motility & Nerve Conditions: IBS, poorly managed diabetes, hypothyroidism (which slows digestive movement), and connective tissue disorders like scleroderma.
Structural & Inflammatory Changes: Crohn’s disease, celiac disease, or a history of abdominal surgeries.
Medications & Secretions: Chronic use of proton pump inhibitors (PPIs) or opioids, and low stomach acid (hypochlorhydria).
Post-Infectious Triggers: A past history of severe food poisoning or acute bacterial gastroenteritis.
How We Diagnose SIBO
An accurate diagnosis requires a thorough clinical evaluation combined with targeted testing.
The SIBO Breath Test
The gold standard for identifying SIBO is a non-invasive hydrogen and methane breath test, which can be performed at home or in our office.
The Process: After an overnight fast, you drink a specialized sugar solution (either lactulose or glucose).
Collection: You collect breath samples every 15 to 20 minutes over a 2- to 3-hour period.
Analysis: Our laboratory analyzes these samples to check for specific rises in hydrogen and methane gases, which indicate bacterial fermentation in the small bowel.
Real-Time Symptom Tracking
To complement your care plan, our specialists may recommend using a pocket-sized personal breath scanner, such as the FoodMarble AIRE 2. While it does not replace a formal clinical breath test for diagnosis, it allows you to measure hydrogen and methane levels in real time right from your smartphone.
This tool is incredibly valuable during the dietary reintroduction phase, helping you and your gastroenterologist pinpoint exactly which foods trigger fermentation and monitor your progress between office visits.
Additional Testing
To rule out other conditions and see the full picture of your health, your doctor may also recommend comprehensive blood work to check for nutritional deficiencies, stool analysis, or an endoscopy/colonoscopy if structural issues are suspected.
Our Multi-Step, Personalized Treatment Plan
Because SIBO is complex, we design customized, phase-based treatment plans tailored to your specific breath test results and health history.
[Phase 1: Clear] ──> Targeted Antibiotics or Herbal Antimicrobials
[Phase 2: Reset] ──> Customized Dietary Protocols (e.g., Low-FODMAP)
[Phase 3: Move] ──> Prokinetics & Addressing Root Motility Causes
[Phase 4: Build] ──> Strategic Microbiome Support & Relapse Prevention
Phase 1: Clear the Overgrowth
The first step is reducing the excess bacteria in the small intestine. We primarily utilize targeted, gut-localized antibiotics like rifaximin (Xifaxan), which work directly in the digestive tract with minimal absorption into the rest of the body. For methane-dominant cases, we often combine rifaximin with neomycin or metronidazole for optimal results.
Natural Alternatives: For patients who prefer or require a botanical approach, we offer evidence-based herbal antimicrobial protocols utilizing targeted essential oils and extracts (such as oregano oil and berberine) that have shown comparable efficacy in clinical studies.
Phase 2: Dietary Modification
Diet is a powerful tool for managing symptoms and keeping bacteria from multiplying during recovery. Our team helps guide you through specific nutritional protocols, which may include the Low-FODMAP diet, a temporary elemental diet, or structured elimination and reintroduction plans to help you find your personal food triggers.
Phase 3: Restore Intestinal Motility
To prevent SIBO from returning—which is common if the underlying cause isn't addressed—we focus heavily on the Migrating Motor Complex (MMC). This is the natural "sweeping wave" of the small intestine. We often prescribe prokinetic agents to keep things moving smoothly and treat any underlying conditions like hypothyroidism or diabetes.
Phase 4: Long-Term Microbiome Support
In the final phase, we focus on rebuilding a resilient, balanced gut. This includes the strategic timing and selection of specific probiotics, prebiotics, and lifestyle adjustments to protect your digestive system for the long term.