IBS vs. SIBO: What’s the Difference?

You're experiencing problems with your gut and you want to know what's going on. We're talking some pretty uncomfortable symptoms here—bloating, constipation, diarrhea, and excruciatingly bad abdominal pain. You've done your research and even though you're pretty sure it's either IBS or SIBO, it's hard distinguishing between the two.

Do you have SIBO or IBS? And how do you know the difference? In this post, we'll help you settle your IBS vs. SIBO dilemma so you can figure out what's going on with your gut.

What Is IBS?

Short for Irritable Bowel Syndrome, IBS is a gut disorder that causes symptoms like abdominal pain, bloating, and bowel movement issues, such as constipation or diarrhea. According to the American College of Gastroenterology, roughly 10-15% of the United States population suffer from this disorder, with only 5-7% of adults actually being diagnosed.

Unfortunately, there isn't a definitive test for diagnosing IBS so the verdict is still out on what exactly causes it. However, there are many different factors that seem to play a role, including:

• Stressful life events (especially occurring in childhood)
• Infections in your GI tract
• Bacterial overgrowth in your intestines
• Food allergies or sensitivities, which can cause digestive issues
• Gut microbe changes
• Irregularities in the nerves of your gut, which can cause abdominal pain, constipation (IBS-D), diarrhea (IBS-C), or change in stool color
• Mental health issues such as depression or anxiety

What Is SIBO?

SIBO, short for small intestinal bacterial growth, occurs when you experience an overgrowth of bacteria in your small intestine. It's caused by low stomach acid (hypochlorhydria). Instead of being cleared out during digestion, bad microbes find a home in your small intestine when your body is low on stomach acid.

Similar to IBS, SIBO can cause painful symptoms like belly pain, nausea, bloating, and can even lead to leaky gut. The intestinal inflammation from SIBO can also impact your skin and cause acne.

Other stomach issues or conditions that have been associated with increasing the risk of developing SIBO include Crohn's disease, celiac disease, scleroderma, diabetes, and any other condition that slows how fast food and waste move through your small intestine.

How to Test for SIBO

There are many types of gut health tests out there that can determine whether or not you have SIBO. Here are some of the more prominent ones:

• Breath test: For SIBO, a breath test looks for hydrogen or methane gas that gets released by a surplus of bad bacteria in your gut. If it's discovered that you have SIBO, research shows that hydrogen in your breath is probably linked to IBS-D, while methane is probably linked to IBS-C, which speaks to the IBS and SIBO connection which we'll get to later a little later in this post.
• Endoscopy: A sample culture is collected from your small intestine to check for bacterial overgrowth.
• Stool test: In recent years, these tests have become widely accepted for their ability to paint a more complete picture of the inner working of your gut, including whether or not you might have SIBO. One type of test that can give you a high-level, bird's-eye view of what's going on in your gut is 16S DNA sequencing. However, if you're looking for something with more detail, consider going with a more comprehensive gut test like whole genome sequencing that's offered here at Sun Genomics. Whole genome sequencing gets into the nitty-gritty of the gut microbiome. It can tell you the genus, species, strain, and even how much there is of any particular microbe in your gut. This level of detail is key to discovering not only SIBO, but can help in addressing a host of underlying gut problems you might be experiencing.

IBS vs. SIBO: Is There a Difference?

The main difference between IBS vs. SIBO stems from the fact that SIBO can be clinically verified, while there isn't really a test that can tell you with certainty whether or not you have IBS.

The fact that it's hard to tell the difference between SIBO and IBS actually makes sense though. People with IBS and SIBO both have more bacteria in their small intestine. A lot of the time, IBS is actually mistaken for SIBO due to their symptoms being so similar.

In fact, recent research has found that:

• More than a third of people with IBS also have SIBO
• People with IBS are roughly 5 times more likely to have SIBO than those without

Fortunately, whether it's SIBO or IBS, there are steps you can take to address these issues, balance out your gut microbiome, and improve your digestive health.

Treatment for SIBO and IBS

When it comes to IBS vs. SIBO treatment, personalized probiotics are a good starting point. There are numerous studies out there that back the use of probiotics to help with IBS and SIBO symptoms. [Zhong et al., 2017] [Tiequn et al., 2015] [Aragon et al., 2010]

In addition to taking probiotics, going on a low FODMAP diet (diet low in fermented carbs) can help manage symptoms associated with SIBO and IBS. The idea behind a low FODMAP diet is that by reducing the number of fermentable carbs you eat, it can help relieve symptoms often associated with SIBO or IBS—like bloating, gas or constipation.

Conclusion: IBS vs. SIBO

Here are a few takeaway points for IBS vs. SIBO:

• IBS and SIBO are two common gut disorders with many overlapping symptoms—such as stomach pain, bloating, gas, diarrhea, and constipation—just to name a few.
• SIBO is caused by low stomach acid that results in an overgrowth of bacteria in your small intestine. On the flip side, what causes IBS isn't exactly known but factors that appear to play a role include bacterial overgrowth in your intestines, infections in your GI tract, and food allergies or sensitivities.
• While SIBO can be tested for using gut health tests like the breath test, stool test, or endoscopy, there isn't a definitive test that can tell you if you have IBS or not. Luckily, you can improve your digestive health, balance out your gut, and help manage symptoms by taking probiotics and following a low FODMAP diet.

If you're interested in learning more about gut health, check out these other posts:

• Alcohol and Gut Health
• 7 Simple Low FODMAP Restaurant Tips
• Saturated Fats: Good or Bad for Your Gut?