Question 1

How is SIBO diagnosed?

Accepted Answer

The current gold standard for clinical diagnosis is a breath test — either lactulose or glucose. The patient drinks a fermentable sugar solution and exhaled breath samples are collected every 15–20 minutes for three hours. A rise in hydrogen of 20 ppm or more within 90 minutes, or any methane reading of 10 ppm or higher, is considered positive under the North American Consensus.

Question 2

How do I prepare for a SIBO breath test?

Accepted Answer

Follow a bland, low-fermentable diet for 24 hours before the test (plain rice, chicken, eggs, clear broth). Fast for 12 hours before the test. Pause probiotics for at least two weeks, and antibiotics for at least four weeks prior. Do not smoke or exercise vigorously the morning of the test.

Question 3

Is a breath test accurate?

Accepted Answer

Breath testing has a sensitivity of roughly 60–70% and specificity of 80–85% for detecting SIBO. It is not perfect, but it is the most accessible and evidence-based test available. Small-bowel aspirate culture is more accurate but invasive and rarely performed outside research settings.

Question 4

What is the low FODMAP diet?

Accepted Answer

Low FODMAP is a temporary elimination of fermentable carbohydrates (oligosaccharides, disaccharides, monosaccharides, and polyols) that feed overgrown bacteria. It is used for symptom relief during and shortly after antimicrobial treatment, typically for six to eight weeks, followed by structured reintroduction. It is not intended as a lifelong diet.

Question 5

Can I stay on a low FODMAP diet long-term?

Accepted Answer

No — and doing so may worsen outcomes. Long-term restriction reduces microbial diversity, which is protective against SIBO recurrence. The reintroduction phase is the whole point: identify individual triggers and expand the diet to its widest sustainable range.

Question 6

What is an elemental diet?

Accepted Answer

An elemental diet is a nutritionally complete formula of pre-digested nutrients (amino acids, simple sugars, and fats) that requires minimal digestion and starves overgrown bacteria. Used for two to three weeks, it achieves remission rates of 80–85% in clinical studies. It is intense and should be undertaken with clinical guidance.

Question 7

Can I drink coffee with SIBO?

Accepted Answer

Small amounts of black coffee are generally tolerated and may actually support motility. Milk (particularly cow's milk) is high in lactose and often problematic; lactose-free milk, almond milk, or lactose-free lattes are usually well tolerated. Sweetened drinks and mocha syrups often contain high-FODMAP ingredients.

Question 8

What are the main symptoms of SIBO?

Accepted Answer

The hallmark symptoms are bloating and abdominal distension (often worsening through the day), excessive gas, abdominal pain or cramping, altered bowel habits (diarrhoea, constipation, or both), and a feeling of fullness disproportionate to how much was eaten. Systemic symptoms include fatigue, brain fog, nutrient deficiencies (particularly B12 and iron), and skin changes.

Question 9

Can SIBO cause fatigue and brain fog?

Accepted Answer

Yes. Bacterial overgrowth interferes with the absorption of B12, iron, and fat-soluble vitamins, which affects energy and cognition. Bacterial byproducts (including endotoxins) can also cross into circulation and produce systemic inflammation, further contributing to fatigue and brain fog.

Question 10

Does SIBO cause weight gain or weight loss?

Accepted Answer

Both are possible. Methane-dominant SIBO (IMO) is associated with weight gain and constipation, likely due to slowed transit and altered energy harvest from food. Hydrogen-dominant SIBO more often causes weight loss through diarrhoea and malabsorption.

Question 11

How is SIBO treated?

Accepted Answer

Treatment follows three phases: (1) Reduce — antimicrobial therapy with either rifaximin (with neomycin added for methane), herbal antimicrobials, or an elemental diet, typically over two to four weeks. (2) Restore — prokinetic agents to support the migrating motor complex and prevent recurrence. (3) Rebuild — a structured reintroduction of foods and, where indicated, targeted probiotic support.

Question 12

What is rifaximin and is it safe?

Accepted Answer

Rifaximin (Xifaxan) is a non-absorbable antibiotic that acts locally in the gut and is considered the most-studied pharmaceutical treatment for SIBO. Because it is not absorbed systemically, side effects are minimal. A typical course is 550 mg three times daily for 14 days.

Question 13

Are herbal treatments as effective as antibiotics?

Accepted Answer

A 2014 Johns Hopkins study found herbal antimicrobial protocols (combinations of berberine, oregano oil, neem, and allicin) achieved similar remission rates to rifaximin — around 46% vs 34%. Herbal protocols typically run 4–6 weeks. Discuss with a knowledgeable practitioner.

Question 14

Will SIBO come back after treatment?

Accepted Answer

Recurrence is common — roughly 40–60% of patients relapse within a year without addressing the underlying cause. This is why phase two (motility support via prokinetics, vagal-nerve work, and root-cause investigation) is essential. SIBO is best understood as a symptom of an upstream motility or structural issue.

Question 15

Should I take probiotics with SIBO?

Accepted Answer

The evidence is mixed and depends on the strain. Lactobacillus and Bifidobacterium species can worsen symptoms during active SIBO. Spore-based probiotics (Bacillus subtilis, B. coagulans) and Saccharomyces boulardii are generally better tolerated and may support recovery post-treatment. Introduce cautiously.

Question 16

How long does SIBO treatment take?

Accepted Answer

The antimicrobial phase is typically two to four weeks. The full recovery — including motility restoration, dietary reintroduction, and addressing root causes — often takes three to six months. Patience is essential; SIBO is a chronic-tendency condition, not a one-visit fix.

Question 17

What is SIBO?

Accepted Answer

SIBO stands for Small Intestinal Bacterial Overgrowth — a condition in which excessive bacteria accumulate in the small intestine, where relatively few should normally reside. These bacteria ferment carbohydrates before the body can absorb them, producing hydrogen, methane, and hydrogen sulfide gases that cause bloating, discomfort, altered bowel habits, and systemic symptoms like fatigue.

Question 18

What causes SIBO?

Accepted Answer

The most common causes are impaired small-intestinal motility (often after a bout of food poisoning), structural abnormalities such as adhesions or diverticula, low stomach acid (frequently linked to long-term proton-pump-inhibitor use), and conditions that slow digestion such as hypothyroidism or diabetes. Chronic stress and post-viral changes to the vagus nerve are increasingly recognised contributors.

Question 19

Is SIBO the same as IBS?

Accepted Answer

No, but they overlap significantly. Studies suggest 60–80% of people diagnosed with IBS test positive for SIBO. IBS is a symptom-based diagnosis; SIBO is a measurable condition confirmed by a breath test. Treating SIBO often resolves what was previously labelled IBS.

Question 20

Is SIBO contagious?

Accepted Answer

No. SIBO develops when a person's own gut environment allows bacteria to overgrow in a place they shouldn't. You cannot catch SIBO from another person.

Question 21

Can children get SIBO?

Accepted Answer

Yes. SIBO can occur at any age. It is under-diagnosed in children, who may present with persistent abdominal pain, bloating, failure to thrive, or a diagnosis of functional abdominal pain. Testing and treatment should be supervised by a paediatric gastroenterologist.

Frequently asked
questions.

Knowledge is the first step to healing.

Frequently askedquestions.

Knowledge is the first step to healing.

Frequently asked
questions.