SIBO: When It’s More Than Just Bloating
Digestive concerns are some of the most common complaints I see in practice and often some of the most persistent. They can flare after travel, a stomach bug, stress, or antibiotic use, or they can seem to appear out of nowhere. For many people, the discomfort becomes so familiar they start thinking it’s just how their body works. They normalize the excessive bloating, the unpredictable bowels, the discomfort. But sometimes, there’s a more specific explanation hiding beneath the surface.
Sometimes, that condition that often gets missed or misdiagnosed is SIBO.
SIBO 101
SIBO stands for Small Intestinal Bacterial Overgrowth. While the large intestine is designed to host a dense, diverse population of bacteria that make up the gut microbiome, the small intestine should be relatively low in microbial life. When bacteria from the colon migrate upward into the small intestine, they begin fermenting food too early in the digestive process. This can lead to gas, inflammation, and a wide range of discomfort.
This premature fermentation disrupts nutrient absorption and contributes to a whole host of digestive symptoms.
Common Signs and Symptoms of SIBO
SIBO can show up in different ways depending on the type of gas produced, the person’s diet, and the underlying cause. Some of the most common signs include:
Bloating, especially after meals and often within one to two hours.
Abdominal pain or tenderness
Excessive gas or belching
Constipation, diarrhea, or alternating between both
Nausea or feeling full quickly
Brain fog or fatigue
Unexplained nutrient deficiencies, especially B12 or iron
For some people, symptoms are tied clearly to specific foods or meal timing. For others, they feel more random, unpredictable, or even constant. Over time, the discomfort can create anxiety around eating. It’s common to start avoiding more and more foods in an effort to control symptoms, which can leave you feel increasingly limited and uncertain about what their body can tolerate, creating a major fear around foods and a distrust of your own body.
Diagnosing SIBO
The most common way to test for SIBO is with a breath test. After consuming a sugar solution such as lactulose or glucose, you then collect breath samples at regular intervals over a few hours. If bacteria are fermenting that sugar in the small intestine, they will produce hydrogen or methane gases that can be measured in the breath.
Breath testing is non-invasive and can be done at home. While it is not perfect, we can use these results in combination with symptom history and clinical context to better understand what is happening in the digestive tract.
Sometimes, even without a clear test result, a person’s experience can strongly suggest bacterial overgrowth or microbiome dysfunction as one piece of the puzzle.
The Importance of a Multifaceted Approach
SIBO is not simply about too many bacteria. It is often a symptom of a deeper disruption in the digestive or nervous system, which allowed the overgrowth to take hold in the first place. Addressing it in a lasting way means going beyond the immediate symptoms. Instead, we also need to understand why those bacteria were able to thrive in the small intestine.
The standard treatment of SIBO is with a course of antibiotics, like rifaximin/xifaxan. Many patients I work with have already been through one or more rounds of of these antibiotics. Sometimes, these treatments bring only temporary relief, with symptoms often returning within months or even weeks. After going through multiple rounds, I find patients are so discouraged.
Another common experience I see is an immense fear around food. When eating becomes linked to bloating, discomfort, or unpredictable reactions, it is natural to become cautious or avoidant. Over time, I will see patients restricting their diets to just a few “safe” foods in an effort to control symptoms. Every single time I see this, it breaks my heart because food is something we should enjoy. While short-term food strategies can sometimes help reduce reactivity, the long-term goal is always to expand food variety and rebuild trust in your body’s ability to digest and absorb with ease.
This is why a more layered and supportive plan is often needed. Instead of chasing symptoms or relying on repeated antibiotics, the focus shifts to creating a more resilient, better-regulated digestive system.
A Holistic Framework for Addressing SIBO
There is no one-size-fits-all approach to SIBO. Every body and every digestive system is different. But for many people, effective care includes support in the following areas:
1. Reducing Bacterial Load
The first phase typically involves addressing the overgrowth itself through targeted treatment. This may include prescription medications or plant-based antimicrobial support. The goal is not to eliminate all bacteria, but to reduce the excess in the small intestine enough to relieve symptoms and create space for healing. This is often a starting point, not the full solution.
2. Restoring Healthy Motility
The small intestine has its own rhythm called the migrating motor complex, which acts as a clearing wave between meals. When this wave slows down due to stress, infections, medication use, or other factors, bacteria have more opportunity to linger and multiply. Supporting healthy motility is essential for both short-term improvement and long-term prevention.
3. Calming Inflammation and Rebuilding the Gut Lining
Overgrowth often leaves the intestinal lining inflamed and reactive. This can lead to poor nutrient absorption, heightened food sensitivity, and continued symptoms even after the overgrowth is reduced. Soothing and repairing the gut lining is an important step toward restoring comfort and function.
4. Reintroducing and Diversifying Food Safely
As symptoms begin to calm, the next step is rebuilding tolerance. The goal is to help people reintroduce foods that may have been avoided and to bring more flexibility, nourishment, and pleasure back into eating. Supporting digestion while gradually expanding the diet helps reduce fear and build confidence in the body’s ability to process food again.
5. Investigating and Addressing Root Causes
Bacterial overgrowth rarely occurs in isolation. There are often underlying contributors that create the conditions for SIBO to develop or return. These may include low stomach acid, thyroid imbalances, scar tissue from abdominal surgeries, ongoing nervous system dysregulation, certain medications, or a history of gastrointestinal infections. Identifying and addressing these factors is key to preventing relapse and supporting long-term digestive health.
SIBO, IBS, or Something Else?
Digestive symptoms are rarely straightforward. Many of the signs associated with SIBO, such as bloating, constipation, or discomfort also appear in irritable bowel syndrome. In fact, some cases of IBS may be driven by undiagnosed SIBO or may involve both conditions at once.
In other situations, what looks like SIBO could be related to food intolerances, general dysbiosis, or slowed motility from another cause. A thoughtful evaluation can help clarify the difference and prevent unnecessary or ineffective treatments.
My Final Thoughts on SIBO
SIBO is not just about symptoms. It is about the state of the digestive ecosystem and how well the body is managing digestion, absorption, and microbial balance. Relief often requires more than just killing bacteria. It requires a plan that also supports motility, repairs the gut lining, investigates the root causes, and helps people feel more comfortable eating again.
For those who have tried multiple rounds of treatment or feel caught in a cycle of food fear and symptom management, there is another way forward. With curiosity, care, and a personalized approach, it is possible to calm the gut, rebuild resilience, and restore confidence in your body.
About the Author
Dr. Hannah is a naturopathic doctor providing whole body adjunctive healthcare to families in Southern Maine. She believes every patient has their own unique health journey, which influences her personalized treatment approach. She has a passion for helping women, mothers and families heal and thrive, all while uncovering the root cause of whatever ails them. Her goal is to empower and guide her patients on the path towards healing the mind, body and soul through natural methods of healing. Dr. Hannah sees patients locally in Portland and Brewer, Maine. Through telehealth, she is happy to serve the people of Lewiston, Ellsworth, Bangor, and all the towns in between!
Disclaimer
The information provided on or through this website is for educational and informational purposes only. This information is not a substitution for proper and personalized medical diagnosis or treatment. Always seek the advice of your physician or trusted healthcare provider before making an adjustments or changes to your healthcare regimen. Natural medicine is not inherently harmless, and therefore it is important to speak with your healthcare providers for personalized medical advice.