Table of Contents
- What Is SIBO and Why Does the Pattern Matter?
- SIBO Testing Methods That Identify Your Pattern
- Treating SIBO With Functional Medicine: The Four-Phase Protocol
- SIBO Dietary Reintroduction: Slow and Staged
- SIBO Relapse Prevention: Why Motility Is the Lever
- Treating SIBO With Functional Medicine Alongside Conventional Care
- Frequently Asked Questions
Last Updated: September 14, 2026
What Is SIBO and Why Does the Pattern Matter?
Small intestinal bacterial overgrowth is a condition where bacteria that normally live in the large bowel move upward into the small intestine and ferment food there. That fermentation produces gas, and the gas produces the bloating, wind and discomfort many people recognise. At Mojo Klinik, we treat it as five distinct patterns rather than one condition, because the pattern decides the treatment.
Think of it like a car service. You would not accept a mechanic who topped up the oil without checking whether the problem was the oil, the fuel line or the battery. Same engine light, three different repairs.
The five patterns we work with are hydrogen-dominant SIBO, hydrogen sulphide SIBO, methanogen overgrowth, fungal overgrowth and mixed pattern. The American College of Gastroenterology clinical guidance on small intestinal bacterial overgrowth groups these under the same umbrella, yet they behave differently in practice. Hydrogen-dominant overgrowth tends to produce loose stools and wind. Methanogen overgrowth, sometimes called methane-dominant SIBO, tends to slow the bowel and cause constipation. Hydrogen sulphide overgrowth often brings a rotten-egg smell and urgency.
Generic advice fails because it treats all five as one. If you have tried a low FODMAP diet, a probiotic and a course of herbs with no lasting change, the pattern was probably never identified.
SIBO Testing Methods That Identify Your Pattern
The test that identifies your pattern is a breath test, and it needs to be read alongside your history, not on its own. A hydrogen breath test measures the gases you exhale after drinking a sugar solution. The timing and size of the rise tells us which pattern is likely at work (pubmed.ncbi.nlm.nih.gov).
Clinical assessment comes first. We ask about the onset of symptoms, recent gastroenteritis, antibiotic use, thyroid history and bowel habits. That story often points to the pattern before the test confirms it.
Testing may include:
- Lactulose or glucose breath testing for hydrogen and methane
- A hydrogen sulphide assessment where available
- Stool analysis to check for dysbiosis and inflammation
- Blood work to rule out thyroid, bile and malabsorption issues
Breath testing has limits. It can miss fungal overgrowth, and results vary between labs. That is why we treat it as one piece of evidence, not a verdict.
Treating SIBO With Functional Medicine: The Four-Phase Protocol
Treating SIBO with functional medicine means working through four phases in order: Prepare, Reduce, Restore, Prevent. The sequence matters more than any single ingredient, because each phase sets up the next. Skip a phase and the result rarely holds.
Here is what each phase involves, and how the five patterns change the approach.
Phase 1: Prepare
We settle the gut before we try to clear it. This phase looks at diet, nervous system load and bowel movement, and it opens the door for biofilm disruption.
Biofilms are protective layers that bacteria build around themselves. Think of them like the film that forms on a sink drain. Water alone will not shift it. You need the right approach to break it down first. Without disrupting biofilms, antimicrobial treatment often stalls because the bacteria are shielded.
In the prepare phase we may use dietary changes, nervous system support and targeted agents that help break down biofilm structure. This runs through the whole reduce phase, not just at the start.
For hydrogen-dominant SIBO, prepare often focuses on reducing fermentable foods that feed the overgrowth. For methanogen overgrowth, we pay closer attention to bowel movement, because slower transit gives methanogens more time to act. For hydrogen sulphide SIBO, we look at sulphur-containing foods and how they are tolerated. For fungal overgrowth, we assess sugar and starch intake. For mixed pattern, we prioritise the dominant pattern first.
Phase 2: Reduce
This is where we lower the bacterial load. Depending on your pattern, that may involve herbal antimicrobials, prescription antimicrobial therapy where clinically appropriate, or a combination. We do not name medicines or doses here, because that decision belongs in a consultation.
The reduce phase looks different for each pattern. Hydrogen-dominant overgrowth may respond to one set of herbal agents. Methanogen overgrowth often needs a different approach, sometimes combining agents that target methanogens specifically. Hydrogen sulphide overgrowth may need a protocol that avoids certain sulphur-containing compounds. Fungal overgrowth requires antifungal support, not antibacterial. Mixed pattern means sequencing or combining approaches.
This is why generic SIBO advice fails. A protocol designed for hydrogen-dominant overgrowth may do nothing for methanogen overgrowth, and may make hydrogen sulphide overgrowth worse.
Biofilm disruption continues through this phase. We also track how you respond, because the plan may need adjusting.
Phase 3: Restore
Once the load is down, we rebuild. That means supporting the gut lining, addressing intestinal permeability, and reintroducing foods slowly. This is also where digestive enzymes and targeted supplementation may assist, chosen for your pattern rather than bought off a shelf.
Restore is not one-size-fits-all. If you have had loose stools, we focus on firming things up. If constipation has been the issue, we support motility. If malabsorption has been a problem, we check nutrient levels and address deficiencies.
We also look at the gut lining itself. Years of overgrowth can leave it inflamed and more permeable. Supporting it may involve specific nutrients, but the foundation is removing the triggers that keep it irritated.
Phase 4: Prevent
The final phase is the one most people skip, and it is the one that decides whether the result holds. We restore motility, support the migrating motor complex and keep prokinetic support going for months, not weeks.
Motility is the movement of food and waste through the gut. The migrating motor complex is the wave of movement that sweeps the gut clean between meals. When it works, bacteria do not get a chance to settle. When it slows, overgrowth returns.
Prokinetic support continues for months. We also address the root causes that keep motility slow, including thyroid function, bile insufficiency, past gastroenteritis and vagal tone. The vagus nerve links the gut and the brain, and stress can quiet it.
|
Phase |
Focus |
Typical Duration |
|---|---|---|
|
Prepare |
Diet, nervous system, biofilm disruption |
2-4 weeks |
|
Reduce |
Herbal or prescription antimicrobials |
4-8 weeks |
|
Restore |
Gut lining, reintroduction, enzymes |
4-8 weeks |
|
Prevent |
Motility, prokinetics, maintenance |
Months |
SIBO Dietary Reintroduction: Slow and Staged
SIBO dietary reintroduction is the process of adding foods back one at a time after the reduce phase, and it takes four to eight weeks. Rushing it is the most common mistake we see.
You will recognise the pattern. You feel better on a restricted diet, so you stay on it. Weeks pass, your food list shrinks, and you feel no closer to normal eating.
A staged approach looks like this:
- Week 1-2: add one low-risk food group every three days
- Week 3-4: reintroduce moderate FODMAP foods in small serves
- Week 5-6: test higher FODMAP foods one at a time
- Week 7-8: build a maintenance list you can actually live with
Keep a simple symptom diary. Note the food, the timing and what followed. Patterns show up over weeks, not days.
SIBO Relapse Prevention: Why Motility Is the Lever
SIBO relapse prevention comes down to motility, which is the movement of food and waste through the gut. When motility slows, bacteria sit in the small intestine longer and the overgrowth returns. The migrating motor complex is the wave of movement that sweeps the gut clean between meals, and it is the lever we focus on.
Relapse happens when only one arm is treated. Diet alone, antimicrobials alone or probiotics alone do not hold. The pattern needs clearing, the gut needs rebuilding, and the motility needs restoring.
What the first 6 to 12 months look like
Most guides stop at eradication. That is the easy part. The harder part is the year that follows.
Here is a typical maintenance plan.
Months 1 to 3: Active support
Prokinetic support continues. We check in regularly, because this is when symptoms can start to creep back. We also review diet. You are not on a restricted plan forever, but you are not eating everything either. The reintroduction phase from earlier continues, slowly.
Months 4 to 6: Taper and test
If things are stable, we may reduce prokinetic support. We test your tolerance for foods that were previously off the list. We also look at the root causes again. Thyroid function can change. Bile flow can change. Stress can change. The plan adjusts.
Months 7 to 12: Maintenance and monitoring
This is where you build a life that does not revolve around your gut. We keep an eye on motility, but the focus shifts to what keeps it working. Sleep. Nervous system regulation. Movement. Meals that do not overload the system.
How we support motility
Motility support is not one thing. It includes:
- Prokinetic support, which may be herbal or prescription, decided in consultation
- Meal spacing, because the migrating motor complex needs gaps between meals to work
- Nervous system support, because vagal tone affects gut movement
- Addressing root causes like thyroid function, bile insufficiency and past gastroenteritis
The vagus nerve links the gut and the brain. Stress can quiet it. That is part of the gut-brain axis, and it is why we ask about sleep and nervous system load.
The part most guides skip
Chronic bloating, food fear and years of normal test results wear people down. That load affects sleep, mood and the nervous system, which in turn affects motility. Naming it is part of the work.
You may recognise this. You feel better, so you relax. Then a stressful month hits, the bloating returns, and you are back where you started. That is not a failure of willpower. It is a sign that the motility arm was not fully supported.
Treating SIBO With Functional Medicine Alongside Conventional Care
Treating SIBO with functional medicine works in parallel with your existing medical care, never instead of it. If you have a gastroenterologist, keep that relationship. We are not here to replace it.
Gastroenterological Society of Australia guidance on gut disorders sets out when specialist review is warranted, and we support that pathway.
What we add is time and depth. Longer consultations let us take a full history, look at functional pathology beyond standard panels, and track how you respond over months. When a case needs a specialist procedure, we say so.
This is where the psychological side matters, and most guides skip it. Chronic bloating, food fear and years of normal test results wear people down. That load affects sleep, mood and the nervous system, which in turn affects motility. Naming it is part of the work.
Mojo Klinik is led by two AHPRA-registered medical doctors with over 60 years of combined practice, based in Neutral Bay. We see people who are not sick enough for a diagnosis and not well enough to feel like themselves.
If you have been told your tests are normal and you still feel unwell, that is exactly the group we work with. A consultation at Mojo Klinik, Neutral Bay, starts with your story.
You have probably tried a lot already. That is not a failure on your part. Treating SIBO with functional medicine is a sequenced process, and the sequence is what most people miss. Mojo Klinik offers longer appointments, functional pathology beyond standard panels, and a protocol built around your pattern rather than a generic list. Book a consultation at Mojo Klinik, Neutral Bay, to get started with a plan shaped around your history.
This article is general information only and is not medical advice. It does not replace an assessment with a qualified professional. Individual results vary. If you have ongoing gut symptoms, book an assessment.
Frequently Asked Questions
How does functional medicine treat SIBO?
It starts with testing to identify which pattern is present, because treating SIBO well depends on the pattern, not just the label. From there, a sequenced protocol runs through four phases: prepare, reduce, restore and prevent. Diet alone, antimicrobials alone or probiotics alone rarely hold on their own. Motility support and root cause work are built in from the start. A consultation at Mojo Klinik, Neutral Bay, is the place to map this out for your situation.
What is the difference between SIBO and IMO?
SIBO means small intestinal bacterial overgrowth. IMO stands for intestinal methanogen overgrowth, where methane-producing organisms dominate rather than bacteria alone. The two need different approaches. Methane-dominant patterns often respond differently to treatment than hydrogen-dominant ones, which is why a breath test that measures both gases matters. Symptoms may suggest one or the other, but only testing confirms the pattern and guides the plan.
Why is SIBO relapse prevention so important after treatment?
Relapse is common when only one part of the picture is treated. The migrating motor complex, the gut’s natural cleaning wave, needs to be working for the small intestine to stay clear. Prokinetic support often continues for months, not weeks. Food reintroduction is staged slowly over four to eight weeks. Addressing root causes such as thyroid function, bile flow and nervous system tone also lowers the chance of symptoms returning.
What does SIBO dietary reintroduction actually involve?
After the reduce phase, foods are brought back in stages rather than all at once. This usually takes four to eight weeks. The aim is to learn which foods you tolerate and to widen your diet safely, not to stay restricted long term. A clinician guides the pace and watches for reactions. If you have been on a restricted diet for a while, a structured reintroduction plan can help you eat more freely again.