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<\/span><\/i><\/p>\nIf you deal with constant bloating, gas, and unpredictable trips to the bathroom, you may have been told you have irritable bowel syndrome (IBS). But there is another, often-overlooked culprit that could be behind those symptoms: small intestinal bacterial overgrowth, or SIBO. The two conditions overlap so much that many people diagnosed with IBS actually have SIBO that has gone unnoticed. Here is what SIBO is, how it connects to IBS, and what you can do about it.<\/span><\/p>\n What Is SIBO?<\/b><\/p>\n SIBO stands for small intestinal bacterial overgrowth. It happens when bacteria that normally belong in your large intestine grow in excessive numbers\u2014or the wrong types show up\u2014in your small intestine, where bacteria should be fairly scarce.<\/span><\/p>\n Those extra bacteria ferment the food you eat before your body can properly absorb it. That fermentation creates gas and kicks off a chain of uncomfortable digestive symptoms. You might also hear about a close cousin called intestinal methanogen overgrowth (IMO), which involves an overgrowth of methane-producing microbes and is often lumped in with SIBO.<\/span><\/p>\n What Are the Symptoms?<\/b><\/p>\n SIBO symptoms look a lot like other tummy troubles, which is part of what makes it tricky to spot. The most common ones include :<\/span><\/p>\n Because the bacteria get in the way of nutrient absorption, long-running SIBO can also lead to deficiencies (like low vitamin B12) and unintended weight loss.<\/b><\/p>\n What Causes SIBO?<\/b><\/p>\n SIBO usually develops when something throws off the systems that normally keep your gut bacteria in check\u2014things like stomach acid, gut movement, and the valve between your small and large intestine. Common triggers include :<\/span><\/p>\n That last one matters more than you might think. In one study, bacterial overgrowth showed up in 53% of people taking a common acid-blocking drug, compared with just 17% on a different medication. Less stomach acid means one of your gut\u2019s natural defenses is turned down.<\/span><\/p>\n How Is SIBO Diagnosed?<\/b><\/p>\n The most common way to check for SIBO is a simple, noninvasive breath test. You drink a sugary solution, and your breath is measured for the hydrogen and methane gases that gut bacteria give off when they ferment that sugar. A bigger-than-normal rise in those gases points to SIBO. There is also a more involved option\u2014sampling fluid directly from the small intestine\u2014but it is invasive and used far less often. One thing to keep in mind: breath tests are not perfect and can sometimes give false results, so they work best alongside your symptoms and history.<\/span><\/p>\n How Is SIBO Linked to IBS?<\/b><\/p>\n This is where SIBO and IBS get tangled together. IBS is a very common gut condition\u2014affecting an estimated 10% to 15% of people in North America\u2014that causes belly pain along with changes in bowel habits. For years it was thought to be mostly stress-related, but we now know it is far more complicated, and an imbalance of gut bacteria (including SIBO) is one piece of the puzzle.<\/span><\/p>\n The symptoms are nearly identical<\/b><\/p>\n Bloating, gas, pain, diarrhea, and constipation are hallmarks of both conditions. That overlap means SIBO can masquerade as IBS\u2014or show up right alongside it\u2014so you often cannot tell them apart on symptoms alone.<\/span><\/p>\n SIBO is more common in people with IBS<\/span><\/p>\n Studies consistently find SIBO more often in people with IBS than in those without. One large review found SIBO in about 35.5% of people with IBS, compared with 29.7% of those without. The link also seems to vary by IBS type\u2014one study found SIBO in over half of people with diarrhea-predominant IBS.<\/span><\/p>\n The evidence is promising, but not the whole story<\/span><\/p>\n It is worth being realistic here. The connection is real, but the research has limits, partly because breath tests are not perfectly reliable and studies define things differently. Experts continue to debate exactly how big a role SIBO plays. The takeaway: SIBO likely drives symptoms for a meaningful share of people with IBS, but it is not the single cause of IBS.<\/span><\/p>\n How Is SIBO Treated?<\/b><\/p>\n The goal of treatment is to calm your symptoms by clearing out the overgrowth. Most plans combine a few approaches:<\/span><\/p>\n Antibiotics<\/span><\/p>\n Antibiotics are the main treatment. Rifaximin, which stays mostly in the gut, is the best-studied option and clears SIBO in roughly 7 out of 10 people. Other antibiotics like metronidazole and ciprofloxacin can work too.<\/span><\/p>\n Diet<\/span><\/p>\n Changing what you eat can support treatment. A low-FODMAP diet\u2014which cuts back on certain fermentable carbs\u2014is commonly used to starve the troublesome bacteria of their favorite fuel. Many SIBO eating plans focus on limiting sugars, some fruits and starchy vegetables, dairy, and grains.<\/span><\/p>\n Probiotics and fixing the root cause<\/span><\/p>\n Some probiotic strains may help. In one trial, people with both IBS and SIBO saw their symptom scores drop by more than 70% with probiotics. However be careful of starting with probiotics without first getting rid of the overgrowth of bacteria as this may lead to more bloating symptoms.<\/span><\/p>\n <\/p>\n A Functional Medicine Approach to Gut Health<\/a><\/p><\/blockquote>\n\n
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