By Dr. Glenn Ezell, CFMP | St. Charles Functional Medicine
If you’ve been told you have IBS, unexplained bloating, gas, constipation, diarrhea, fatigue, food reactions, or persistent gut symptoms that “nothing seems to fix,” there is a high chance the real issue has been missed.
That issue is called SIBO – Small Intestinal Bacterial Overgrowth.
And it is one of the most common root causes of chronic digestive and inflammatory symptoms we see at St. Charles Functional Medicine.
What Is SIBO?
SIBO occurs when bacteria that belong in the large intestine migrate upward and overgrow in the small intestine—where they do not belong.
The small intestine is designed for nutrient absorption, not fermentation.
When bacteria move in, they begin fermenting your food before you can digest it — leading to:
• Gas & bloating
• Abdominal pressure or pain
• Constipation, diarrhea, or both
• Food reactions
• Nutrient deficiencies
• Fatigue and brain fog
• Skin issues
• Anxiety and mood symptoms
Most people are told they simply have IBS — but IBS is a description, not a diagnosis. SIBO is often the root cause.
Why Conventional Testing Often Misses SIBO
Standard labs, scopes, and stool tests frequently come back “normal.”
Yet symptoms continue.
That’s because SIBO lives in the small intestine, which most routine testing does not properly assess.
Functional medicine uses specialized breath testing that measures hydrogen, methane, and hydrogen-sulfide gases produced by bacteria in the small intestine — giving us direct insight into what is actually happening.
The Root Causes of SIBO
SIBO does not just “appear.”
It is almost always driven by deeper dysfunction, including:
• Poor gut motility (slow migrating motor complex)
• Low stomach acid
• Chronic stress & adrenal dysfunction
• Thyroid imbalance
• Food sensitivities & inflammation
• Prior antibiotic use
• Scar tissue / prior abdominal surgery
• Mold or toxin exposure
Unless these root causes are addressed, SIBO almost always returns.
Why Diet Alone Does Not Fix SIBO
Low-FODMAP and elimination diets can temporarily reduce symptoms — but they do not eliminate bacterial overgrowth or restore gut function.
This is why many people feel stuck on restrictive diets for years, afraid to eat normally again.
True healing requires:
• Identifying the type of SIBO
• Reducing the overgrowth
• Repairing motility, stomach acid, and digestion
• Rebuilding the microbiome
• Removing the root cause drivers
How St. Charles Functional Medicine Treats SIBO
We use a personalized, root-cause protocol — not a one-size-fits-all plan.
Your care may include:
• Advanced SIBO breath testing
• Gut healing & anti-inflammatory nutrition
• Targeted botanical or antimicrobial therapy
• Motility & digestion support
• Hormone & thyroid optimization
• Stress/adrenal healing
• Microbiome restoration
The goal is not just symptom relief — it is long-term healing and food freedom.
Do You Have SIBO?
If you struggle with:
✔ Chronic bloating
✔ IBS
✔ Constipation or diarrhea
✔ Heartburn
✔ Food sensitivities
✔ Fatigue
✔ Brain fog
✔ Skin issues
✔ Anxiety
✔ Autoimmune conditions
There is a strong chance SIBO is part of your picture.
Ready to Get Answers?
At St. Charles Functional Medicine, we help patients uncover and heal the true root causes of gut dysfunction — so they can finally feel normal again.
🌐 www.StCharlesFunctionalMedicine.com
📞 Call 636-486-7044
