IBS vs SIBO: What's the Difference?
Could your IBS symptoms actually be related to SIBO?
Many people are diagnosed with Irritable Bowel Syndrome (IBS) after experiencing bloating, constipation, diarrhoea, abdominal discomfort, food reactions or unpredictable bowel habits.
For some people, the diagnosis helps explain their symptoms.
For others, symptoms continue despite dietary changes, supplements, medications or lifestyle modifications.
This is often where questions about Small Intestinal Bacterial Overgrowth (SIBO) begin.
In clinic, I regularly work with patients across Maroochydore, Forest Glen and the Sunshine Coast who have been told they have IBS but continue to struggle with bloating, food reactions, constipation, diarrhoea or digestive discomfort despite treatment.
What Is IBS?
IBS (Irritable Bowel Syndrome) is a functional digestive condition characterised by symptoms such as:
• Bloating
• Abdominal discomfort
• Excess gas
• Diarrhoea
• Alternating bowel habits
• Food sensitivities
IBS is a syndrome rather than a single disease, meaning two people can have similar symptoms but very different underlying drivers.
What Is SIBO?
Small Intestinal Bacterial Overgrowth (SIBO) occurs when excessive bacteria accumulate within the small intestine.
These bacteria ferment carbohydrates and produce gases that may contribute to:
• Bloating after meals
• Visible abdominal distension
• Excessive gas
• Food reactivity
• Constipation
• Diarrhoea
• Abdominal discomfort
Many people with SIBO report feeling significantly worse after eating, particularly after consuming fermentable carbohydrates.
Why IBS and SIBO Are Often Confused
One reason IBS and SIBO are frequently discussed together is because the symptoms overlap significantly.
Both conditions may involve:
• Bloating
• Excess gas
• Constipation
• Diarrhoea
• Abdominal pain
• Food sensitivities
Because symptoms can appear almost identical, some people diagnosed with IBS later discover that SIBO may be contributing to their presentation.
This does not mean everyone with IBS has SIBO.
However, it does mean that symptom labels do not always explain why symptoms are occurring.
Not sure why you're bloated? Read: Why Am I Bloated All The Time?
Why Some People With IBS Investigate SIBO
The diagnosis of IBS describes symptoms.
SIBO may help explain one possible mechanism contributing to those symptoms.
For some people, investigating digestive function, gut motility, previous infections and fermentation patterns may provide additional information beyond the IBS label alone.
This is particularly relevant when symptoms are persistent, recurring or difficult to manage.
How Is SIBO Diagnosed?
Breath testing is currently the primary method used to assess for SIBO.
The test measures gases produced by bacteria within the digestive tract and may help identify patterns associated with bacterial overgrowth.
Read more about SIBO Testing & Digestive Support.
Book a Consultation
If you're experiencing bloating, constipation, diarrhoea, abdominal discomfort or persistent IBS-like symptoms, a consultation may help identify the factors contributing to your presentation.
Appointments available in Maroochydore, Forest Glen and via Telehealth Australia-wide.