SIBO, IMO & FDO – What Can Really Be Behind “Irritable Bowel Syndrome”

johannaschneiderhe
Mar 19
4 min read

(And Why Holistic Balance Takes Time)

By Johanna Schneider – Holistic Health Coach

Many people who experience digestive problems are diagnosed with Irritable Bowel Syndrome (IBS) – often prematurely and without a thorough investigation. But IBS is actually an umbrella term. Behind it, there can be very different causes, including SIBO, IMO, or FDO.

Here, I share my personal experience and holistic knowledge, and I want to help you better understand your symptoms.

(Not a substitute for medical diagnosis or treatment.)

Book a free initial consultation ✅

🔍 What are SIBO, IMO, and FDO?

SIBO – Small Intestinal Bacterial Overgrowth

→ Classic SIBO

→ Too many hydrogen producing bacteria in the small intestine

→ Often leads to diarrhea, bloating, belching, abdominal pain, brain fog

IMO – Intestinal Methanogenic Overgrowth

→ Technically not classic SIBO, because it involves methanogens (archaea), not bacteria

→ Still shows up on the test in the same way

→ Typical symptoms: severe constipation, bloating like “pregnant belly,” slow digestion, tendency for weight gain

FDO (also called FIMO) – Dysbiosis in the Large Intestine→ Certain bacteria produce hydrogen sulfide (H₂S)→ Common symptoms:

Bloating, abdominal pressure
Nausea
Strongly smelling (foul, sulfur-like) gas
Fatigue, brain fog

→ This type is harder to test for (not all labs detect it, some only indirectly)

All three are types of small intestinal dysbiosis, but they are not the same. Many people suffer for years with symptoms because they are simply diagnosed with “IBS” without understanding the real cause.

❓ How does small intestinal dysbiosis develop?

There isn’t just one cause – it’s usually a combination of several factors. The most common are:

Stress → slows down gut motility & weakens digestion
Frequent snacking → food stays too long in the small intestine
Hypothyroidism → slows down gut function
Gastrointestinal infections → can disrupt the system long-term
Spoiled food → if the gut lining never fully recovers afterward
Too much or too little stomach acid
Unbalanced diet
Weakened immune system
Vegetarian or vegan diet without proper nutrient compensation
Lack of regular meal routines
Genetic factors

And one factor hardly anyone talks about:The valve between the small and large intestine (ileocecal valve).If it doesn’t close properly or is damaged, bacteria can migrate back into the small intestine.

⚡ Typical Symptoms

(Based on personal experience – not a diagnosis)

From my own experience, I have noticed:

Bloating (like being six months pregnant)
Excess gas
Pain or pressure in the abdomen
Belching
Brain fog (feeling like your mind is “clouded” – concentration, clarity, and thinking are difficult, as if your brain is in standby mode)
Fatigue
Malabsorption (in my case: sorbitol & fructose)
Irregular digestion
Mood swings due to the gut-brain axis

It doesn’t only affect the gut – it can influence the entire nervous system, energy levels, and mental clarity.

🧪 Diagnosis: Why the Right Test Matters

Many people don’t realize that there are different breath tests – and not all are equally reliable.

👉 Lactulose Breath Test Recommended because lactulose reaches the entire small intestine and can reveal dysbiosis.

👉 Glucose Breath Test Only tests the upper part of the small intestine – can give false negatives.

I also personally tested for:

Lactose
Sorbitol
Fructose

…which helped me discover that I react strongly to sorbitol and fructose.

🌿 Why a Holistic Approach Is So Important

SIBO doesn’t develop overnight – and it doesn’t go away overnight either.

The reality:

❌ There is no quick fix

❌ Impatience makes it worse

❌ The body needs time

Many people get frustrated after 3–4 months – but often that’s not enough. Sometimes it takes a year or longer for the system to fully stabilize.

What helped me:

Adjusting nutrition (phased & individualized)
Regulating stress (nervous system work, laughter yoga, TriLochi®)
Acupuncture
No snacks between meals
Ensuring optimal nutrient intake
Stabilizing sleep & routines
Practicing patience & acceptance
Eliminating bacteria from the small intestine (with plant-based antibiotics) and rebuilding the gut step by step with targeted nutrients and supplements

The Key Takeaways:

👉 I stopped fighting against my body.

👉 I learned to listen.

🌟 My Personal Experience

After several tests, dietary adjustments, and a holistic plan, my fructose malabsorption disappeared after 6 months and my sorbitol malabsorption after about 9 months – today I can eat everything again.

I have experienced: