Small Intestinal Bacterial Overgrowth – SIBO
Do You Struggle with Chronic Bloating, Gas, or Digestive Discomfort?
If you experience persistent bloating, abdominal pain, diarrhea, or constipation that hasn’t responded to standard treatments, you may be living with Small Intestinal Bacterial Overgrowth, commonly known as SIBO. This often-overlooked condition affects millions of Americans and is frequently misdiagnosed as irritable bowel syndrome (IBS).
Our board-certified gastroenterologists specialize in identifying and treating SIBO using evidence based diagnostic testing and individualized treatment plans designed to restore your gut health and improve your quality of life.
What Is SIBO? (Small Intestinal Bacterial Overgrowth)
SIBO occurs when bacteria that normally live in the large intestine migrate into and overpopulate the small intestine. The small intestine is supposed to have relatively few bacteria, and when that balance is disrupted, the overgrown bacteria begin fermenting carbohydrates before proper digestion can occur, producing excess hydrogen and/or methane gas.
This bacterial imbalance interferes with nutrient absorption and causes a cascade of uncomfortable and debilitating symptoms that can significantly impact daily life.
Key Facts About SIBO
- Affects an estimated 6 to 15% of healthy adults and up to 80% of people diagnosed with IBS
- Can cause malabsorption of critical nutrients including iron, B12, and fat soluble vitamins
- Often goes undiagnosed for years because its symptoms overlap with many other GI conditions
- Is a recognized, diagnosable, and treatable medical condition
Common Signs and Symptoms of SIBO
Gastrointestinal Symptoms
- Bloating and abdominal distension (often worse as the day progresses)
- Excessive gas and belching
- Abdominal cramping and pain
- Diarrhea, constipation, or alternating between both
- Nausea
- Feeling of fullness quickly after eating
Systemic Symptoms
- Unexplained fatigue and brain fog
- Nutritional deficiencies (iron-deficiency anemia, B12 deficiency, low vitamin D)
- Unintended weight loss
- Joint pain
- Skin issues such as rosacea or eczema (associated with gut-skin axis dysfunction)
Types of SIBO
There are three main types of SIBO, classified by the type of gas produced by the overgrown bacteria. Identifying the type is critical to selecting the most effective treatment:
- Hydrogen-Dominant SIBO: The most common form. Excess hydrogen gas is produced, typically causing diarrhea and loose stools.
- Methane-Dominant SIBO (IMO – Intestinal Methanogen Overgrowth): Caused by methane-producing archaea rather than bacteria. More commonly associated with constipation.
- Hydrogen Sulfide SIBO: A newer category associated with rotten egg-smelling gas, diarrhea, and significant discomfort.
What Causes SIBO? Risk Factors & Underlying Conditions
SIBO rarely develops in isolation. It is most often the result of an underlying condition that disrupts normal intestinal motility, anatomy, or immune function. Identifying and addressing the root cause is essential to preventing recurrence.
Common Risk Factors
- Irritable Bowel Syndrome (IBS), very strong association
- Celiac disease or other malabsorption syndromes
- Diabetes (Type 1 and Type 2), affects gut motility
- Hypothyroidism, slows intestinal movement
- Crohn’s disease or other inflammatory bowel conditions
- Prior abdominal surgeries or structural abnormalities
- Chronic use of proton pump inhibitors (PPIs) or opioids
- Scleroderma or other connective tissue disorders
- Low stomach acid (hypochlorhydria)
- A history of acute bacterial gastroenteritis or food poisoning (post infectious IBS/SIBO)
How We Diagnose SIBO: Breath Testing & Evaluation
The SIBO Breath Test
The gold standard for SIBO diagnosis is the lactulose or glucose hydrogen/methane breath test. This non-invasive, at-home or in-office test works by:
- The patient fasts overnight and then drinks a sugar solution (lactulose or glucose).
- Breath samples are collected every 15–20 minutes over 2–3 hours.
- A laboratory analyzes the samples for elevated levels of hydrogen and/or methane gas.
- Our physician reviews the results in the context of your full symptom history.
At-Home Breath Testing with FoodMarble
For patients who want to monitor their symptoms between clinical visits, we may recommend the FoodMarble AIRE 2 device. FoodMarble is a pocket-sized breath tester that measures hydrogen and methane gas in real time after eating, allowing you to identify personal food triggers and track your gut health from home.
While FoodMarble does not replace a formal clinical breath test for diagnosing SIBO, it can be a valuable complement to your care plan — helping you and your gastroenterologist see patterns in your digestive response to specific foods, monitor progress during treatment, and stay proactive between appointments. Patients find it especially useful during the dietary reintroduction phase to pinpoint which foods cause fermentation and symptoms.
Additional Diagnostic Tools
- Comprehensive blood work to assess nutritional deficiencies
- Stool analysis to evaluate the microbiome and rule out other conditions
- Colonoscopy or endoscopy if indicated to rule out structural or inflammatory causes
- Evaluation for underlying conditions that may be driving SIBO
SIBO Treatment: A Personalized, Multi-Step Approach
Phase 1: Antibiotic or Antimicrobial Therapy
The primary treatment for SIBO involves targeted antibiotics or herbal antimicrobials to reduce bacterial overgrowth. The most used antibiotic is rifaximin (Xifaxan), which works locally in the gut with minimal systemic absorption. For methane dominant SIBO, a combination of rifaximin and neomycin or metronidazole is often more effective.
For patients who prefer or require a natural approach, evidence based herbal antimicrobial protocols using oregano oil, berberine, and other botanicals have shown comparable efficacy in clinical research.
Phase 2: Dietary Modification
Diet plays a critical role in managing SIBO symptoms and supporting recovery. Our team works closely with patients and can coordinate care with registered dietitians to implement appropriate dietary strategies, which may include:
- Low-FODMAP diet — reduces fermentable carbohydrates that feed bacteria
- Elemental diet — a liquid formula that starves bacteria while nourishing the patient
- Specific Carbohydrate Diet (SCD) or Bi-Phasic Diet
- Gradual reintroduction protocols to identify personal food triggers
Phase 3: Addressing Underlying Causes & Motility
To prevent SIBO relapse, which is common without addressing root causes, we focus on:
- Optimizing the Migrating Motor Complex (MMC) using prokinetic agents to keep the intestine moving and prevent bacterial stagnation
- Treating underlying conditions such as hypothyroidism, celiac disease, or diabetes
- Evaluating and adjusting medications that may contribute to SIBO (e.g., PPIs, opioids)
- Addressing structural issues if present
Phase 4: Gut Microbiome Support & Prevention
- Strategic use of probiotics (timing and selection matter in SIBO)
- Prebiotics and gut-supportive supplements as appropriate
- Long-term dietary and lifestyle modifications
- Regular follow-up and repeat breath testing to monitor for recurrence
Why Choose Unio Specialty Care for SIBO?
Choosing Unio Specialty Care for SIBO treatment means receiving expert, individualized care from a team dedicated to resolving complex digestive conditions at their source. Our gastroenterologists combine advanced diagnostic capabilities, including convenient breath testing and comprehensive evaluations, to identify underlying causes and guide precise treatment. Every care plan is tailored to your unique symptoms, test results, and health history, with a whole person focus that considers your overall health, medications, and lifestyle. By coordinating care with dietitians and other specialists, we deliver an integrated approach that not only treats bacterial overgrowth but also helps prevent recurrence and support long term digestive wellness, with ongoing follow up to track progress and refine your treatment plan as needed.
