At a glance
| Question | Quick answer |
|---|---|
| What is it? | Bacteria overgrowing in the small intestine |
| The hallmark sign | Bloating 30 minutes to 2 hours after eating |
| Often mistaken for | IBS, food intolerance, a sensitive stomach |
| How it’s confirmed | A hydrogen and methane breath test |
What SIBO actually is
SIBO stands for small intestinal bacterial overgrowth: an excess of bacteria in the small intestine, where relatively few should live. As those bacteria ferment your food they produce gas, and that gas is what you feel as bloating, wind and discomfort.
The hallmark sign is timing. Bloating that arrives 30 minutes to 2 hours after eating, leaving you flat at breakfast and distended by evening, is the pattern that most often points to an overgrowth rather than a general sensitivity.
It is confirmed with a simple hydrogen and methane breath test, which is why it is worth testing rather than guessing.
What it’s often mistaken for
IBS. IBS names the symptoms. SIBO can be the actual driver underneath them, and a significant share of IBS cases involve an underlying overgrowth.
A food intolerance. Reactions to onion, garlic, fibre or FODMAPs can come from bacteria fermenting those foods, rather than a fixed intolerance to them.
“Just bloating” or stress. Dismissed as normal, when a treatable overgrowth is producing the gas.
How we’d help
At Melbourne Natural Medicine the SIBO Breath Test is run as part of functional testing and interpreted by a naturopath alongside your full picture, so you leave with a plan rather than just a number. In-clinic or Telehealth, Australia-wide. Not ready for a full consult? Begin with a free 15-minute Dispensary Quick Script.
Related reading: what the timing of bloating after eating tells you, and leaky gut symptoms.
Common signs and symptoms
One sign alone is rarely the whole story. It’s the cluster, and the pattern over time, that points to a treatable cause.
- Bloating after eating — flat in the morning, distended by evening. The number one clue.
- Excess gas or burping — frequent wind as bacteria ferment your meals.
- Cramping or pain — eases briefly after wind or a bowel motion.
- Diarrhoea, constipation, or both — bowels that swing unpredictably.
- Food reactions — flares after onion, garlic, fibre or FODMAPs.
- Fatigue and brain fog — poor absorption leaves you tired and foggy.
Please read first
See your GP first for unexplained weight loss, blood in your stool, persistent vomiting or fever. A SIBO test is not a substitute for ruling these out.
Frequently asked questions
What is SIBO?
SIBO is an excess of bacteria in the small intestine. As they ferment food they produce gas, causing bloating, wind and discomfort 30 minutes to 2 hours after eating.
What causes SIBO?
Usually slowed gut motility, low stomach acid, a previous gut infection, some medications, or chronic stress. Anything that lets bacteria build up in the small intestine.
Is SIBO the same as IBS?
No. IBS describes the symptoms, SIBO is a specific, testable cause. A significant share of IBS cases involve underlying SIBO.
Can SIBO be treated?
Often yes, though it can recur if the underlying cause isn’t addressed. Good care works to reduce the overgrowth, restore digestion, then target the root driver.
Stop Guessing About the Bloating.
You don’t have to put up with a stomach that swells every afternoon. Let’s find out what’s driving it, and build a plan around the cause rather than the symptom.
