SIBO Symptoms: When Bloating and Gut Trouble Won’t Go Away
By Dr. Amy Putrus-Schnell, DC CFMP — The Healing Place, Franklin, TN
You eat something, and within an hour your belly is swollen and tight, like you swallowed a balloon. The pressure shows up no matter how “clean” you eat. There’s gas, cramping, and a bathroom pattern that swings from one extreme to the other, sometimes in the same week.
Maybe a doctor told you it’s just stress, or handed you a generic “eat more fiber” plan that made things worse. You’ve cut out dairy, then gluten, then a dozen other foods, and you still feel like your gut is running the show. It’s exhausting to feel this uncomfortable and still not have a name for what’s happening.
One explanation that gets missed far too often is SIBO. It’s a real, recognized condition, and once you understand what’s driving it, the path forward usually gets clearer. Below, we’ll walk through what this condition actually is, the signs to watch for, how testing works, and how a root-cause approach digs deeper than chasing one flare at a time.
What Is SIBO?
SIBO stands for small intestinal bacterial overgrowth. Your gut is supposed to hold trillions of bacteria, but most of them belong in the large intestine, farther down. The trouble starts when too many of them settle and multiply in the small intestine, where they’re not meant to thrive.
That misplaced overgrowth causes problems for a simple reason: the bacteria ferment the carbohydrates you eat before your body can absorb them properly. The byproduct is gas, and a lot of it. According to a comprehensive review in Gastroenterology & Hepatology, that fermentation in the small intestine is what drives the gas, distension, and discomfort so many people describe.
The small intestine is also where you absorb most of your nutrients, so when bacteria crowd that space, digestion and nutrient uptake can both suffer. That’s why this condition can leave you feeling run down, not just bloated. It’s a gut problem with whole-body ripple effects.
The Most Common Symptoms of SIBO
The classic SIBO symptoms tend to cluster around digestion, and they often get worse after meals. The hallmark is bloating that feels out of proportion to what you ate, frequently paired with visible abdominal distension by the end of the day.
Alongside that, many people deal with excess gas and flatulence, cramping or abdominal pain, and unpredictable bowel habits. For some it means diarrhea; for others it tips toward feeling backed up, and plenty of people swing between the two. Reduced appetite, nausea, and a vague “everything I eat bothers me” feeling are common too.
What I notice with patients is that these complaints rarely show up in isolation. It’s the pattern that tells the story: pressure that builds through the day, gut trouble that flares with certain foods, and a sense that no elimination diet has fully cracked it. When those pieces line up, this condition is worth investigating rather than guessing at.
What Causes It?
This is usually a sign of something else going on in your gut, not a random event. The most common root cause is a slowdown in motility, the wave-like muscle movement that sweeps food and bacteria through your gut and into the bowel below. When that sweeping action stalls, the bacteria linger and multiply where they shouldn’t.
The Cleveland Clinic points to several contributors, including impaired digestive movement, low stomach acid, and structural issues such as adhesions or scarring from prior surgery. Conditions that affect the nerves and muscles of the digestive tract can quietly set the stage long before any signs appear.
This is why a “kill the bugs and move on” mindset so often disappoints. If the underlying reason the bacteria are accumulating never gets addressed, the overgrowth tends to return. Finding the driver behind your particular case is the whole point of a root-cause approach.
When Antibiotics and Medications Set the Stage
Many people are surprised to learn about SIBO from antibiotics. Antibiotics are sometimes part of treating an overgrowth, but rounds taken for other reasons can also disrupt the delicate balance of gut bacteria and leave the door open for the wrong organisms to take hold.
Other medications can contribute too. Long-term use of acid-reducing drugs like proton pump inhibitors lowers stomach acid, and since stomach acid is one of your body’s natural defenses against bacterial overgrowth, reducing it can make the upper gut more hospitable. Certain medications that slow the bowel can have a similar effect by dampening that wave-like movement.
None of this means these medicines are villains. It means the gut is a connected system, and understanding your full history, including past prescriptions, helps explain why an overgrowth developed in the first place.
Is It This, or IBS?
This condition and irritable bowel syndrome share so many features that they’re frequently confused, and the two can overlap in the same person. Gas, cramping, and erratic bowel habits show up in both, which is part of why so many people bounce between explanations for years.
Research suggests a meaningful share of people diagnosed with IBS may actually have an underlying overgrowth feeding their discomfort. That doesn’t mean every such case is the same, but it does mean the question is worth asking, especially when nothing has responded to standard advice.
The practical difference comes down to testing and root cause. Rather than settling for a label that only describes how you feel, the goal is to find out what’s actually happening in your gut so the plan can match the problem.
How SIBO Testing Works
If your story points this direction, the right test moves you from guessing to knowing. This is the part I want you to understand best, because good testing changes everything about how a plan gets built. We don’t treat a hunch; we test, interpret, and then act.
The most common option is the SIBO breath test, which is non-invasive and can be done at home or in a clinic. After you drink a measured sugar solution, usually lactulose or glucose, you collect samples over a few hours. Because the bacteria in your small intestine produce hydrogen and methane gas when they ferment that sugar, this test measures those gases to flag an overgrowth and even suggest its type. The research review noted above describes lactulose and glucose breath testing as the standard, accessible way to assess for small intestinal bacterial overgrowth.
One test rarely tells the whole story on its own. That’s why we often pair it with a stool test like the GI-MAP, which maps the broader bacterial picture in your gut, screens for imbalances, and checks markers of inflammation and digestion. Reading these tests together, alongside your symptoms, gives a far clearer view than any single number from any single test.
If you’re weighing which tests make sense for you, our functional lab testing page walks through the panels we use most. The right test depends on your history, so we decide together rather than ordering everything at once. Whatever we test, the goal is the same: connect what your gut is doing to why it’s doing it.
A Functional Medicine Approach to SIBO Treatment in Franklin, TN
Functional medicine starts with a different question than “what drug treats this?” It asks why your gut became a friendly place for an overgrowth in the first place, then builds a plan around that answer. A whole-body approach weighs your digestive movement, your stomach acid, your stress, your history, and your nutrition as one connected picture.
In my practice, I’ve worked with patients who came in convinced they were simply “sensitive to everything,” after years of shrinking their food list with no lasting relief. When we finally ran the right test and looked at the full picture together, the pattern often pointed back to a sluggish, slowed-down gut that no elimination diet was ever going to fix on its own. I’m careful never to promise a quick answer, but I’ve seen how much changes once the root cause comes into focus.
For SIBO treatment in Franklin, TN, that root-cause lens is what shapes the plan. Whether the path involves targeted gut support, restoring healthy motility, addressing nutrition, or a combination, the aim is the same: support your body in correcting the imbalance and lowering the odds it comes back.
The Nervous System and Your Gut
Here’s a connection that often gets overlooked: your gut and your nervous system are in constant conversation. The same nerves that calm your body also drive the muscle action that keeps your gut sweeping bacteria through, so when your nervous system is stuck in a stressed, “on alert” state, that housekeeping can slow right down.
This is where our two sides work together. Alongside the functional medicine workup, Dr. Anthony Putrus, DC uses a neurologically-focused approach that includes an INSIGHT scan, a non-invasive assessment that measures how your nervous system is responding to stress. Looking at nervous system regulation next to your gut findings is part of how we approach the whole person rather than one complaint.
Supporting a calmer, better-regulated nervous system won’t replace addressing the bacteria directly, but it may help your body do its own housekeeping more effectively. For families across Brentwood and Williamson County who have chased gut trouble for years, that whole-body view is often the missing piece.
Diet, Nutrition, and Lifestyle Support
Food plays a real role in calming symptoms, even though it isn’t the root cause by itself. The most studied eating pattern here is the low FODMAP diet for SIBO, which temporarily limits certain fermentable carbohydrates that feed bacteria and fuel gas. Many patients report meaningful relief from bloating and pressure while following it.
The catch is that this is meant to be a tool, not a forever plan. Staying too restrictive for too long can starve the beneficial bacteria you want to keep and make good nutrition harder than it needs to be. We use diet to ease discomfort while we work on the underlying driver, then carefully widen your choices as your gut stabilizes.
Beyond what’s on your plate, the basics matter more than any single supplement: steady meals, restful sleep, stress management, and gentle movement that supports healthy digestion. For moms and dads juggling a busy household, small consistent changes usually beat a dramatic overhaul you can’t sustain.
Frequently Asked Questions
What are the warning signs to watch for?
The most common signs are abdominal distension and pressure after meals, excess gas, cramping or abdominal pain, and erratic bowel habits that swing between loose stools and feeling backed up. Many people also notice nausea, a reduced appetite, and food reactions that seem to keep growing.
How is it diagnosed?
The standard tool is a breath test using lactulose or glucose, which measures the hydrogen and methane gases bacteria produce in the small intestine. We often pair that with a stool test such as the GI-MAP and interpret both alongside your symptoms and history.
Can it be caused by antibiotics?
It can be a contributing factor. Rounds of antibiotics, along with long-term acid-reducing medications and anything that slows the gut, can disrupt the balance of bacteria and make an overgrowth more likely. Your medication history is part of understanding the root cause.
Does the low FODMAP diet cure it?
No single diet is a cure. A low FODMAP diet may help reduce gas and pressure in the short term by limiting the foods bacteria ferment, but it works best as a temporary tool while the underlying cause is addressed, not as a permanent restriction.
Take the Next Step Toward Gut Answers
If you’ve spent months or years feeling at the mercy of your gut, you deserve a closer look at what’s actually driving it. At The Healing Place in Franklin, TN, our functional medicine team helps you connect what you’re feeling to its root cause and build a plan around your life, not a generic checklist.
You can learn more about Dr. Amy and her functional medicine approach on her provider bio, or reach out to our Franklin, TN office to talk through whether testing makes sense for you. Patients come to us from across Franklin, Spring Hill, and Cool Springs for exactly this kind of whole-body, root-cause care.
Related Functional Medicine Reading
Because SIBO so often overlaps with other root-cause patterns, you may also find these guides from our Franklin, TN functional medicine team helpful: histamine intolerance, the gut-brain connection, functional medicine for autoimmune disease, insulin resistance, and mold toxicity.
This article is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. It does not establish a doctor-patient relationship. Individual results vary, and SIBO is a medical condition that should be evaluated and managed with a qualified healthcare provider. Always consult your provider about your specific symptoms and before making changes to your diet or care.