DR MARIA MACKEY
Mojo Klinik · Neutral Bay Sydney
IBS and SIBO: investigation and care.
Two linked gut conditions. Both worth investigating properly.
IBS (Irritable Bowel Syndrome) describes the symptoms. SIBO (small intestinal bacterial overgrowth) is one of the things often driving them.
Both are testable. Both are treatable.
SOUND FAMILIAR?
You will recognise yourself in some of these.
Most patients arrive carrying one or more of these.
- You have an IBS diagnosis and the conversation with your GP has run out of road
- You have heard about SIBO and want to know if it explains what you are experiencing
- You have chronic bloating, abdominal pain, alternating constipation and diarrhoea, or excessive gas
- Your symptoms began after food poisoning, a stomach bug, or international travel
- The low-FODMAP diet has helped, but only partially or temporarily
- Your list of food intolerances keeps growing
- You have other symptoms alongside the gut ones: fatigue, brain fog, skin issues, nutrient deficiencies
- You have been told you have IBS but no one has tested for SIBO
We see this every day. There is almost always a clinical explanation. Pulling on it is what we do.
WHAT IBS AND SIBO ACTUALLY ARE
IBS and SIBO are not the same thing, though they overlap.
IBS is a description of symptoms (bloating, pain, altered bowel habit) without structural disease. A clinical pattern, not a cause. Treatable through identifying the actual drivers, not the label.
SIBO is bacteria normally in the large intestine colonising the small intestine. Measurable through breath testing, treatable through targeted antimicrobial protocols.
IBS functional medicine is the discipline of investigating which is which, and what else is contributing.
Key fact: a 2023 meta-analysis in Frontiers in Pharmacology found a pooled SIBO prevalence of approximately 38% in patients with an IBS diagnosis based on breath testing. For many people carrying an IBS label, SIBO is a major part of the picture, and it is testable.
"My IBS patients have usually done the rounds. GP. Gastroenterologist. Normal bloods, clean colonoscopy. Strict FODMAP. Still bloated, still uncomfortable. The piece they have not been offered is a proper investigation of what is actually going on in there."
A CLINICAL PATTERN MAP
The four SIBO patterns.
Different patterns. Different treatment.
HYDROGEN – DOMINANT
The most commonly identified pattern.
Diarrhoea-predominant.
Urgency, loose stools.
Often post-infectious.
Responds to standard antimicrobial protocols.
METHANE – DOMINANT (IMO)
Slower to respond. Different approach required.
Constipation-predominant.
Bloating after meals.
Floating stools.
Methanogens treated first; treatment staged.
HYDROGEN SULPHIDE
Requires specific testing.
Rotten-egg-odour gas.
Diarrhoea, sulphur intolerance.
Fatigue common.
Distinct treatment pathway from H2 or methane
MIXED PATTERN
Both hydrogen and methane elevated.
Alternating bowel habit.
Food sensitivities multiply.
Longest to clear.
Methanogens first, then hydrogen-producers. Staged.
All four patterns are identifiable through lactulose breath testing.
OUR THREE – PHASE APPROACH
Investigation,then targeted care,then restoration.
The third phase is what determines whether the work holds.
Phase 1
Investigate
Detailed history. Breath testing. Comprehensive stool analysis where indicated. Review of past pathology.
Phase 2
Treat
Plan built specifically for what was found. Evidence-based herbal antimicrobials calibrated to the SIBO type, dietary support, prescription medication where clinically appropriate.
Phase 3
Restore
The phase that determines whether the work holds. Restoring motility, gradual food reintroduction, addressing the underlying drivers.
THE FOUR SIBO PATTERNS
Different SIBO types respond to different approaches.
We test before we treat.
Hydrogen-dominant
- Typically diarrhoea-predominant, urgency, loose stools
- The most commonly identified pattern
Methane-dominant (IMO)
- Almost always involves constipation
- Slower to respond
- Requires a different approach
Hydrogen sulphide
- Rotten-egg-odour gas and diarrhoea
- Requires specific testing and a distinct approach
Mixed pattern
- Both hydrogen and methane elevated
- Bloating with alternating bowel habit, food sensitivities multiplied over time
- Treatment is staged: methanogens first (the slower half of the picture), then hydrogen-producers
- Usually takes longer to clear
Testing is matched to your specific picture. The cost of any privately billed test is explained before you agree to it. Lactulose breath testing (the SIBO test) is non-invasive, completed at home in 2 to 3 hours. Comprehensive stool microbiome analysis where indicated. Intestinal permeability markers. Organic acids testing (OAT) where the clinical picture suggests it. Food sensitivity panels where ongoing food intolerance is part of the picture. Coeliac screen if not previously done.
IS MOJO KLINIK RIGHT FOR YOU?
Is this approach right for you?
IT'S A FIT IF
- You have an IBS label and have never been tested for SIBO
- You have daily bloating, urgency, or alternating bowel habit
- Your symptoms started after food poisoning, gastro, or travel
- The low-FODMAP diet has helped only partially or you cannot get off it
- Your food intolerances are growing rather than improving
- You have other symptoms alongside the gut ones (fatigue, fog, skin)
NOT A FIT IF
- You want a quick repeat script with no investigation
- You want a generic gut protocol without testing
- You have known structural gastrointestinal disease that needs gastroenterology, not functional medicine
HOW TO START
Three ways to start with us.
The right one depends on whether you want a fast-track focused on the gut, a deeper big-picture investigation, or Dr Varipatis’s specific expertise.
OPTION 1
Gut Assessment with Dr Maria Mackey
- 45 minutes
- $390 in-person
- $410 Zoom
Medicare rebate available for in-person initial consultations
The fast-track. If your concern is primarily gut-related and you want to move quickly to a
structured plan. Dr Maria assesses your gut
health and determines the right approach for
your specific picture.
OPTION 2
Mojo New Patient Appointment with Dr Maria Mackey
- 1 Hour
- $490 in-person
- $510 Zoom
Medicare rebate available for in-person initial consultations
The deep dive. If you want a full big-picture investigation, including hormones, fatigue, inflammation, and other systems alongside the gut.
OPTION 3
Mojo New Patient Appointment with Dr Emmanuel Varipatis
- 1 Hour
- $480 in-person
- $500 Zoom
Medicare rebate available for in-person initial consultations
Dr Varipatis brings 40+ years of experience and a deep environmental medicine perspective. Best if your gut history is tangled with chronic infections, suspected heavy metal or chemical exposures, or other complex multisystem contributors.
FAQ
FrequentlyAsked Questions.
How much does an IBS or SIBO consultation cost at Mojo Klinik?
The fastest path is the Gut Assessment with Dr Maria Mackey: 45 minutes, $390 in-person or $410 by Zoom, with a Medicare rebate available for inperson initial consultations. The deeper investigation is the Mojo New Patient Appointment: 1 hour, $490 with Dr Mackey or $480 with Dr Varipatis. SIBO breath testing, where indicated, is billed separately by the testing lab.
"Patients ask whether the Gut Assessment is enough or whether they need the full hour. If the gut is the dominant story, the Gut Assessment does the job. If the gut is tangled up with hormones, fatigue, or other systems, the Mojo New Patient Appointment is the better entry point."
78% of patients with IBS in Australia report that their condition significantly affects daily life and work, yet only a minority have ever been investigated for SIBO. Australian IBS Insights Survey, 2024.
How do I know if I have SIBO or just IBS?
You cannot tell from symptoms alone, because they overlap. The reliable way to differentiate is lactulose breath testing, a non-invasive test you can complete at home in 2 to 3 hours that measures hydrogen and methane gas
produced by bacteria fermenting the test substrate in your small intestine.
"When a long-term IBS patient asks whether she also has SIBO, my answer is straightforward. We test. There is no point guessing when the test is non-invasive and gives us real information."
A 2023 meta-analysis in Frontiers in Pharmacology found a pooled SIBO prevalence of approximately 38% in patients with an IBS diagnosis based on breath testing.
How long does the IBS or SIBO programme take?
For most patients, the active treatment phase is 4 to 8 weeks. The full programme including restoration is 12 to 16 weeks. Methane-dominant SIBO is often slower and may require additional cycles. A typical patient is stable on a maintenance plan by month 4 to 6.
"I tell patients to budget four months. The first month is testing and stabilising. The middle two are the active work. The last is restoration and food reintroduction. By the end, most patients have a clear picture of what their gut needs to stay well."
Can SIBO be treated without antibiotics?
Yes. Herbal antimicrobial protocols are an evidence-supported first-line
approach for many SIBO presentations, often used alongside or instead of
prescription antibiotics. Dr Mackey selects the approach based on your SIBO
subtype (hydrogen-dominant, methane-dominant, or hydrogen sulphide),
your prior treatment history, and your individual situation.
"For most IBS-SIBO patients I lead with a herbal antimicrobial protocol. The evidence is strong, the side effect profile is favourable, and the relapse rates compare well with antibiotic-only approaches. Where prescription antibiotics are clinically indicated, we use them. Tools, not the whole toolkit."
The Chedid et al. clinical study at Johns Hopkins, since referenced in multiple subsequent reviews, found herbal antimicrobials achieved 46% SIBO eradication versus 34% for the prescription antibiotic comparator, with significantly fewer adverse effects.
I did SIBO treatment elsewhere and the symptoms came back. Why?
The most common reason is no proper restoration phase. If the underlying
drivers (motility, low stomach acid, ongoing inflammation, post-infectious
changes) were not addressed, the conditions for the picture to return are still
in place. Our third phase focuses on this directly.
"SIBO recurrence is what separates a thorough programme from a quick fix. Eradicating bacteria is the easy part. Restoring the conditions in which they cannot easily come back is the work that matters. That is the phase I never skip."
A 2022 systematic review in the American Journal of Gastroenterology documented SIBO recurrence rates of 13 to 44% within 6 months when the restoration phase was inadequate
What about the low-FODMAP diet?
The low-FODMAP diet is useful as a short-term symptom management tool, not a long-term treatment for SIBO. It works by reducing the fermentable substrate available to bacteria, which reduces gas and bloating. The risk is using it as a permanent solution rather than a diagnostic and stabilising step.
"The most common mistake I see is a strict low-FODMAP diet held for two or three years without supervised reintroduction. The diet was not designed to live there. It starves the microbiome, narrows tolerance, and entrenches the pattern. We use it strategically, then reintroduce systematically."
A 2024 review in Nutrients confirmed that prolonged FODMAP restriction beyond 6 to 8 weeks is associated with reduced microbial diversity and is not recommended as a long-term dietary pattern.
Do I need a GP referral?
No. You can book directly with Dr Mackey or Dr Varipatis at Mojo Klinik. You
are welcome to keep your GP for acute care and general health. We can write
to your GP with our findings and plan where useful. We do not replace your
GP and we do not assume that relationship.
AN INVITATION
Ready to be properly investigated?
One hour. Your full history. The right tests. A real plan. Book your
first appointment online, or call reception on 02 9133 8500.
WHERE
Suite 11, 40 Yeo Street
Neutral Bay NSW 2089
HOURS
Mon – Fri 8:30am – 5:00pm
Selected Saturdays by arrangement