SIBO vs. IBS: Why Small Intestinal Bacterial Overgrowth Is Often Misdiagnosed and What You Can Do About It
Digestive discomfort is incredibly common, but for many people, the diagnosis they receive doesn’t fully explain their symptoms. One of the most misunderstood GI conditions today is Small Intestinal Bacterial Overgrowth (SIBO), a condition that often looks like Irritable Bowel Syndrome (IBS), is frequently misdiagnosed as IBS, and may go untreated for years.
If you've struggled with bloating, stomach pain, or unpredictable digestion and felt like something deeper was going on, you’re not alone. Here's why SIBO is commonly confused with IBS, what symptoms to look for, and what remedies may help.
Why SIBO Is So Commonly Misdiagnosed as IBS
For decades, IBS has been a catch-all diagnosis. It describes symptoms, not their cause.
IBS is typically diagnosed when someone has:
- Abdominal pain
- Bloating
- Diarrhea, constipation, or both
- Symptoms lasting at least 3 months
But here’s the problem: SIBO causes all of these symptoms too and often more intensely.
Many studies now show that up to 60% of people diagnosed with IBS actually have underlying SIBO. Why the overlap?
1. Symptoms look nearly identical
Both conditions cause:
- Gas and bloating
- Cramping
- Diarrhea or constipation
- Food sensitivities
- A “reactive” gut after meals
This makes it easy for SIBO to get labeled as IBS with no further testing.
2. Standard IBS testing doesn’t detect SIBO
Conventional IBS workups rarely include breath testing, the primary test for detecting SIBO. Without it, doctors often assume IBS.
3. Treatments for IBS don’t fix SIBO
Anti-spasm medications may offer mild relief, but they don’t address the bacterial overgrowth driving SIBO symptoms. So people continue to struggle for years.
What Is SIBO, Exactly?
SIBO happens when bacteria build up in the small intestine, an area that normally has very few microbes. This excess bacteria:
- Ferment carbohydrates too early
- Create gas in the wrong part of the digestive tract
- Damage nutrient absorption
- Trigger inflammation
- Slow or speed up motility
This is why symptoms can be severe and unpredictable.
Symptoms of SIBO (and How They Differ From IBS)
While SIBO and IBS look similar, SIBO often causes more post-meal reactions and nutrient issues.
Common SIBO symptoms include:
Digestive Symptoms
- Immediate bloating after eating (within minutes)
- Excessive gas or burping
- Constipation, diarrhea, or alternating patterns
- Stomach pain or pressure
- Frequent nausea
- Acid reflux or heartburn
- Food intolerances, especially to carbs and fiber
Non-Digestive Symptoms
These are much more common in SIBO than IBS:
- Fatigue
- Brain fog
- Unexplained weight loss or weight gain
- Vitamin deficiencies (especially B12, iron, or fat-soluble vitamins)
Many people who “don’t feel right” and are told they have IBS actually have untreated SIBO.
How SIBO Is Diagnosed
The main diagnostic tool is a hydrogen and methane breath test, which measures gas levels after drinking a sugar solution. Elevated gases indicate overgrowth in the small intestine.
If you suspect SIBO, this is the test to request. It can be ordered through a gastroenterologist or functional medicine practitioner.
Remedies & Treatment Options for SIBO
Treating SIBO involves reducing bacterial overgrowth, restoring healthy motility, and repairing the gut lining. Natural remedies that can help:
· Digestive Enzymes- help break down food when your body is struggling to do so
· Gaps Diet- involves reducing carbs, starches and sugar while healing the gut lining with homemade chicken broth
· Probiotics- soil based probiotics or lactobacillus (for non-methane based SIBO) balance gut bacteria
Many people feel relief for the first time in years once SIBO is properly addressed. With proper testing, targeted treatment, and dietary support, most people see dramatic improvements.
*This information is not meant to be taken as medical advice, please consult with your doctor.