SIBO stands for small intestinal bacterial overgrowth. It happens when too many bacteria build up in the small intestine, a part of the gut that normally holds far fewer bacteria than the colon. The most common symptom is bloating, and the usual way to test for it is a simple breath test.
At Elive Health, we meet a lot of people who have lived with daily bloating for years and been told to just live with it. Sometimes SIBO is part of that story. Here is what we want you to know about how it shows up, how it is tested, and what treatment can look like.
What Is SIBO, in Plain Terms?
Your small intestine is where most digestion and nutrient absorption happen. Your body has a few built-in ways to keep bacteria there under control. Stomach acid, the steady wave-like movement of the gut (called motility), and the valve between the small and large intestine all help.
When one of those defenses slows down or breaks down, bacteria can multiply where they do not belong. They start fermenting your food early, which creates gas. That gas is a big reason people with SIBO feel so bloated after meals.
There is also a methane-producing version. The American College of Gastroenterology (ACG) suggests calling this intestinal methanogen overgrowth, or IMO, because the microbes that make methane are technically archaea rather than bacteria. Methane is linked with constipation, so people with IMO often feel backed up instead of rushing to the bathroom.
Common SIBO Symptoms
According to the ACG guideline, bloating is the most common symptom. Other common ones include:
Belly pain or discomfort
Gas and a visibly swollen belly
Diarrhea
Constipation, especially with the methane type
Over time, SIBO can also affect how well you absorb nutrients. Medical reviews describe vitamin B12 deficiency and trouble absorbing fat, which can lower vitamins A, D, and K and sometimes lead to weight loss you did not plan for.
One important point: no single symptom is specific to SIBO. Bloating and belly pain overlap with IBS, celiac disease, food intolerances, and other conditions. That is why testing matters more than guessing.
What Causes SIBO?
SIBO usually has an underlying driver. The ACG guideline and other medical reviews list these as known risk factors:
Slowed gut movement from diabetes, low thyroid (hypothyroidism), scleroderma, or opioid medications
Past abdominal surgery, such as gastric bypass or surgery that removes the valve between the small and large intestine
Low stomach acid, including long-term use of acid-reducing medications called PPIs (the research here is mixed, so this does not mean everyone on a PPI has SIBO)
Other conditions such as celiac disease, IgA deficiency, and cirrhosis
Older age and female sex
SIBO also overlaps with IBS. A subset of people with IBS test positive for SIBO, though researchers have not settled which one leads to the other.
Since diabetes is on that list, a gut workup at Elive often includes a look at blood sugar and insulin markers too. That fits how we build every plan, through a cardiovascular prevention lens. Your gut, your metabolism, and your long-term heart health all belong in the same conversation.
How Is SIBO Tested?
The most common test is a breath test. You drink a sugar solution (glucose or lactulose) and then breathe into collection tubes at set times over a couple of hours. The lab measures hydrogen and methane in each sample.
Based on the North American Consensus on breath testing, a hydrogen rise of 20 parts per million (ppm) or more within 90 minutes is considered positive for SIBO. A methane level of 10 ppm or more at any point points toward IMO.
Breath testing is helpful, but it is not perfect. Medical reviews note there is no fully validated gold standard test for SIBO, so we always read results alongside your symptoms and history. Your test kit comes with prep instructions, usually a special diet the day before and an overnight fast. Following them closely makes the results more reliable.
The ACG suggests breath testing for people with IBS-type symptoms, people with suspected motility problems, and people with symptoms after past abdominal surgery. It suggests against testing people on PPIs who have no symptoms.
Depending on your story, we may also look at a GI-MAP stool test, food sensitivity testing, and basic labs such as B12, vitamin D, iron, and thyroid. A stool test mainly reflects what is happening in the colon, so it adds to the picture but does not diagnose SIBO on its own. You can read more about these options on our gut health testing and care page.
How Is SIBO Treated?
Treatment depends on your test results, your symptoms, and what is driving the overgrowth. Common pieces of a plan include:
Antibiotics. The ACG suggests antibiotics for people who have symptoms and a positive SIBO result. Rifaximin is one of the most studied options. It is FDA-approved for IBS with diarrhea, traveler's diarrhea, and a liver-related condition called hepatic encephalopathy. It is not FDA-approved specifically for SIBO, so using it for SIBO is considered off-label. Other antibiotics are sometimes used too.
Herbal antimicrobials. One small retrospective study from 2014 found that herbal therapy cleared SIBO on follow-up breath tests at a rate similar to rifaximin. It was a chart review rather than a randomized trial, so the evidence is limited. Herbal products are not FDA-approved to treat SIBO, and quality varies between brands. We only recommend them as part of a supervised plan.
Diet changes. A short-term lower-fermentation approach, such as a low-FODMAP diet, may ease symptoms for some people. The evidence is limited, and these diets are meant to be temporary and guided, since cutting too many foods for too long can backfire on nutrition.
Probiotics. The ACG guideline notes there is not consistent evidence that specific probiotics treat SIBO. We decide on these case by case.
Addressing the root cause. This may mean reviewing medications, supporting thyroid or blood sugar health, or improving gut motility. This is the part we spend the most time on.
Why SIBO Can Come Back
SIBO has a reputation for returning, and research backs that up. In one study of 80 adults cited by the ACG, recurrence was about 13% at 3 months, 28% at 6 months, and 44% at 9 months after treatment. The guideline names treating the underlying cause as the main way to prevent it from coming back.
That is why our plans focus on the why, along with the bacteria. If slowed motility, a medication, or blood sugar is part of the picture, it needs attention too.
How We Approach SIBO at Elive Health
Gut symptoms rarely happen in isolation. We start with a full history, order testing only when the results will change your plan, and build care around what we find. For people who want ongoing support while they work through gut issues, hormones, or metabolic health, our 4-, 6-, and 10-month health programs give you regular check-ins and room to adjust.
If your symptoms look more like IBS, our post on a functional medicine approach to IBS walks through that side of things. For a bigger-picture view, see how functional medicine looks at gut health.
We see patients in person at our New Braunfels clinic and virtually anywhere in Texas.
SIBO FAQs
Can SIBO go away on its own?
We do not have good research showing SIBO reliably clears up on its own. Because it usually has an underlying cause, like slowed gut movement or past surgery, it makes more sense to find and address that cause than to wait it out.
Is SIBO the same as IBS?
No. They are different diagnoses with overlapping symptoms. Some people with IBS test positive for SIBO, and treating the SIBO may help their symptoms. Others with IBS do not have SIBO at all.
What foods should I avoid with SIBO?
Some people find short-term relief on a lower-fermentation diet, such as low-FODMAP, which limits certain sugars and fibers that bacteria feed on. The evidence is limited, and these diets are meant to be short-term. It is best to do this with guidance so you do not end up cutting more foods than you need to.
Can I do a SIBO breath test at home?
Yes, in most cases. The breath test is usually done with a kit at home. You follow the prep instructions, collect your breath samples on a set schedule, and mail the kit back to the lab.
Do probiotics help SIBO?
The research is mixed. The ACG guideline notes there is not consistent evidence supporting specific probiotics for SIBO. Since the evidence is unclear, this is worth talking through with your provider before you start one.
Ready to Get Answers About Your Bloating?
If you are tired of guessing what is behind your bloating, gas, or belly pain, we would love to help you find out. Book a consultation with Elive Health for an in-person visit in New Braunfels or a virtual visit from anywhere in Texas. Questions first? Call us at (830) 376-0035.
This article is for education only and is not medical advice. Talk with your own provider before starting any new treatment.
Sources
Pimentel M, Saad RJ, Long MD, Rao SSC. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. Am J Gastroenterol. 2020, 115(2):165-178. https://doi.org/10.14309/ajg.0000000000000501
Rezaie A, et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. Am J Gastroenterol. 2017, 112(5):775-784. https://pubmed.ncbi.nlm.nih.gov/28323273/
Sorathia SJ, Chippa V, Rivas JM. Small Intestinal Bacterial Overgrowth. StatPearls, NCBI Bookshelf. Updated 2023. https://www.ncbi.nlm.nih.gov/books/NBK546634/
U.S. Food and Drug Administration. XIFAXAN (rifaximin) prescribing information, 2023. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/021361s031lbl.pdf
Chedid V, et al. Herbal Therapy Is Equivalent to Rifaximin for the Treatment of Small Intestinal Bacterial Overgrowth. Glob Adv Health Med. 2014, 3(3):16-24. https://pmc.ncbi.nlm.nih.gov/articles/PMC4030608/