Hydrogen Breath Test for SIBO in Singapore

The hydrogen breath test is a safe, non-invasive procedure designed to detect small intestinal bacterial overgrowth (SIBO). SIBO occurs when excessive bacteria accumulate in the small intestine, disrupting normal digestion and nutrient absorption.

By measuring hydrogen in your breath, which is produced when unabsorbed sugars are fermented by bacteria, the test identifies whether bacterial overgrowth is contributing to your digestive issues. Results from this test allow our gastroenterologist to develop a personalised management plan that targets both symptoms and underlying causes.

How the Hydrogen Breath Test for SIBO works

The breath test tracks bacterial fermentation in the small intestine to provide insight into gut health. The process involves:

Patients refrain from all food and drinks for 8 to 12 hours before the test. This ensures that baseline hydrogen levels reflect only your body’s response to the test solution.
A pre-test sample is collected to determine your starting hydrogen levels.
Patients drink a measured amount of glucose, which serves as a substrate for bacterial fermentation.
Breath samples are taken every 15 to 20 minutes over 1 to 2 hours to track hydrogen production.
If excessive bacteria are present, glucose fermentation produces hydrogen, which is absorbed into the bloodstream and exhaled.
A rapid or elevated rise of hydrogen indicates SIBO, guiding further treatment.

hydrogen breath test for SIBO Singapore. — Hydrogen breath testing offers a non-invasive way to assess bacterial activity in the small intestine and identify patterns linked to SIBO.

SIBO hydrogen production bacterial overgrowth. — Excess bacteria in the small intestine ferment sugars earlier than expected, leading to hydrogen production that can be detected through breath analysis.

What is the purpose of the Hydrogen Test for SIBO?

Hydrogen breath testing is performed to identify whether bacterial overgrowth in the small intestine is responsible for persistent digestive symptoms. Patients who experience symptoms such as frequent bloating may benefit from the test, especially when these issues have not been explained by prior evaluations.

The results help clinicians pinpoint the underlying cause of symptoms and guide targeted interventions. This can include dietary modifications tailored to bacterial activity, addressing factors that slow gut motility or prescribing antibiotics when necessary, allowing for a more precise and effective approach to managing SIBO.

Benefits of the Hydrogen Breath Test for SIBO

The breath test offers several advantages for patients with suspected SIBO, such as:

Non-invasive and safe for adults and children.
Objective measurement of bacterial overgrowth to guide treatment.
Supports dietary and medical interventions, helping reduce symptoms and improve digestive comfort.
Reduces the need for invasive procedures in many cases.

Preparing for a Hydrogen Breath Test for SIBO

It is essential to undergo proper preparation, as it ensures accurate and interpretable results. Before the test, you are expected to:

Fasting – no food or drinks (except water if permitted) for 8 to 12 hours before the test to ensure baseline hydrogen is reliable.
Dietary adjustments – avoid high-fibre vegetables, legumes and carbonated beverages for 24 hours before, as they can alter gut fermentation patterns.
Lifestyle considerations – smoking and vigorous exercise should be avoided before the test.
Medication guidance – certain antibiotics, probiotics or medications affecting gut flora may need to be paused as directed by our gastroenterologist.

Following these instructions reduces the likelihood of repeating the test and ensures results accurately reflect small intestinal bacterial activity. If the baseline is not obtained, then the test will be rescheduled for another day.

medications affecting the hydrogen breath test SIBO preparation. — Some medications can alter gut bacteria or gas production, which may interfere with breath test accuracy if not paused beforehand.

endoscopy structural causes of SIBO Singapore. — Endoscopy can assess structural or anatomical changes in the digestive tract that may contribute to bacterial overgrowth in the small intestine.

Understanding Hydrogen Breath Test results

The test results provide actionable insights into gut health, which aids in outlining a comprehensive management plan. It indicates that:

Normal result – minimal hydrogen rise indicates balanced bacterial activity and normal small intestinal function.
Abnormal result – early or significantly elevated hydrogen peaks suggest SIBO. Interpretation is combined with your symptoms, dietary habits and medical history to create a comprehensive management plan.

Alternatives to Hydrogen Breath Testing for SIBO

If our gastroenterologist determined that a hydrogen breath test is not suitable for your condition, alternative options may be considered. This includes:

Small bowel aspirate and culture – direct measurement of bacteria, used selectively due to invasiveness.
Nutrient deficiency assessments – blood tests for vitamin B12, iron or folate to detect malabsorption.
Imaging or endoscopy – reserved for suspected structural issues in the small intestine.

Who is suitable for Hydrogen Breath Testing for SIBO

Hydrogen breath testing is appropriate for individuals experiencing persistent or unexplained digestive symptoms. Some of the suitable candidates include:

People with bloating, excessive gas or abdominal discomfort who have not responded to standard dietary adjustments.
Individuals experiencing diarrhoea, constipation or alternating bowel habits with unclear cause.
Patients with nutrient deficiencies, such as vitamin B12 or iron malabsorption, are potentially linked to bacterial overgrowth.
Those seeking clarity beyond prior investigations, such as endoscopy, colonoscopy or blood tests.

Our gastroenterologist will review your medical history, symptoms and lifestyle to determine whether hydrogen breath testing is appropriate.

gastroenterologists care for SIBO digestive symptoms in Singapore. — Specialist evaluation helps link symptoms, test findings and underlying gut function to guide targeted and sustainable SIBO management.

Comprehensive SIBO Testing and gut care at Andrea’s Digestive Clinic

Our approach to SIBO goes beyond procedures alone. Many patients arrive with prior investigations and are seeking practical guidance for persistent or recurrent symptoms. At our clinic, Dr Andrea Rajnakova and our in-house dietitian, Ms Veronica Cavallini, work together to provide coordinated medical and nutritional care.

This collaboration ensures:

Integrated care – medical assessment and dietary strategies are aligned from the outset.
Thorough evaluation – we consider lifestyle, diet, gut motility, previous treatments and medical history, not just test results.
Personalised plans – tailored management supports symptom control, nutritional adequacy and long-term digestive wellbeing.

As the only gastroenterology clinic in Singapore with an in-house dietitian, we offer a unique, holistic approach to SIBO care that helps patients regain confidence in their digestive health.

Book a Hydrogen Breath Test in Singapore

If you experience persistent bloating, abdominal discomfort or irregular bowel habits, hydrogen breath testing may provide the clarity you need. Contact us to book a consultation. It is important to remember that an early assessment leads to an early intervention.

Frequently Asked Questions

Is the hydrogen breath test safe?

Yes. It is non-invasive and suitable for adults and children. The test involves no needles or radiation.

How long does the test take?

The procedure usually lasts 1–2 hours, including baseline and multiple breath samples.

Can I eat before the test?

No. Fasting for 8 to 12 hours is essential for accurate results. Our gastroenterologist will provide specific instructions.

Does the test diagnose all types of SIBO?

The hydrogen breath test is most effective for detecting hydrogen-producing bacteria. Methane-producing SIBO may require specialised testing, which can be discussed with your gastroenterologist.

What if I already had an endoscopy or colonoscopy?

Even if prior investigations were normal, the hydrogen breath test can identify bacterial overgrowth that is not visible on endoscopy, providing actionable guidance for symptom management.

How are the results used?

Results help guide dietary strategies, medical management and follow-up plans to reduce symptoms and improve digestive health.

Dr. Andrea Rajnakova

MD, Hons (Slovakia), M.Med, Hons (Slovakia), PhD (NUS), MMed (SG), MRCP (UK), FAMS in Gastroenterology (SG)

Your Insides Matter More Than You Know

This article has been medically reviewed by Dr Rajnakova

Dr Rajnakova is a Consultant Gastroenterologist with over 30 years of experience in gastroenterology, therapeutic endoscopy and digestive health. A PhD scholar in gastric cancer with multiple awards and publications, she is committed to providing holistic, patient-centred care, with special interests in celiac disease, food allergies, diet and nutrition.