Digestive issues are incredibly common, and they’re also incredibly frustrating.

You might be experiencing bloating, gas, or abdominal discomfort and chalking it up to stress or something you ate. But what if there’s more to the story?

Research suggests that a condition called SIBO may be more common than previously thought, with various studies detecting its presence, at times, associated with many different gastrointestinal complaints.

However, SIBO symptoms overlap across many conditions, making SIBO tricky to diagnose. Consequently, many people struggle for years without knowing what’s causing their discomfort.

To combat that, let’s walk through what SIBO is, how to recognize potential SIBO symptoms, and what to do if you suspect you’ve developed this condition.

What Is SIBO?

When patients come to me experiencing frustrating digestive issues, I consider many potential diagnoses. First and foremost, we have to check for the seven red flags of abdominal pain, which could indicate a serious problem requiring immediate attention. These include localized pain, loss of appetite, fever, restlessness, radiating pain, nausea and vomiting, or rectal bleeding.

Once we’ve ruled out more urgent concerns, I consider several possibilities, including SIBO.

SIBO, or small intestinal bacterial overgrowth, is exactly what it sounds like: an overgrowth of bacteria in the small intestine.

In a healthy digestive system, the small intestine and large intestine each have their own bacterial populations living in a comfortable, symbiotic relationship. The small intestine primarily handles absorption of nutrients, while the large intestine focuses on reabsorption of fluids to prevent dehydration.

When bacteria that normally live in the large intestine back up into the small intestine and take over, problems begin. This bacterial migration results in inflammatory processes and immune system activation. That’s when SIBO symptoms start to appear.

Several factors can lead to SIBO. Reduced intestinal motility (the movement that pushes food through your digestive tract), structural abnormalities in the small intestine, certain medications, and reduced stomach acid production can all increase the risk of developing SIBO. Specific diseases, such as diabetes and chronic pancreatitis, can contribute to these risk factors.

Know the Hallmark SIBO Symptoms

A combination of various symptoms often leads me to consider SIBO as a potential diagnosis. The most common SIBO symptoms include:

• Abdominal bloating: The most prominent complaint, patients describe feeling uncomfortably full or swollen, especially after eating.
• Increased gas production: Includes upper gas (burping) or lower gas (flatulence).
• Abdominal pain: Can range from mild discomfort to more significant cramping.
• Changes in bowel habits: Includes diarrhea, constipation, or alternating between the two.
• Nausea: Sometimes present, adding to overall digestive discomfort.

FODMAP Foods and Why They Matter

Certain foods promote bacterial fermentation in the small intestine, worsening SIBO symptoms. These are called FODMAP foods, or Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols foods.

Common FODMAP foods include beans, onions, garlic, cauliflower, mushrooms, and yogurt. When you consume high-FODMAP foods in the presence of SIBO, the bacterial overgrowth ferments them inside your small intestine, resulting in excessive gas production and inflammation. This triggers or worsens the bloating, pain, and other SIBO symptoms that make life so uncomfortable.

When SIBO Persists: Long-Term Symptoms

If a SIBO infection is present for an extended period, you can develop seemingly unrelated symptoms. These are often due to nutritional deficiencies caused by poor absorption in the small intestine:

• Vitamin B12 deficiency is particularly common and can result in weakness, fatigue, and brain fog.
• Iron deficiency may develop, potentially leading to anemia.
• Weight loss can stem from poorly absorbed nutrients.

These symptoms can result from many other types of non-gut-related problems as well, which is why proper evaluation by a well-trained physician is so important.

Ruling Out Other Conditions

The nonspecific nature of SIBO symptoms is what makes them so challenging to diagnose. Other conditions can cause similar digestive issues, some of which are more concerning than SIBO:

• Inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis, can present with similar symptoms but are much more serious diseases.
• Irritable bowel syndrome, or IBS, is another possibility. This complex condition deals with general sensitivity of the gut, though some research suggests SIBO may contribute to IBS in a percentage of cases.
• Acid reflux can cause bloating, nausea, and discomfort similar to SIBO symptoms, but has different risks and requires a different approach for treatment.

Symptoms often overlap significantly, which is why we can’t assume SIBO is the problem based on symptoms alone. Proper testing is essential to reach an accurate diagnosis.

SIBO Testing, Treatment, and the Benefits of Functional Medicine

In my practice, I use a noninvasive SIBO breath test to evaluate potential SIBO symptoms in patients. The test involves consuming a sugar called lactulose, which feeds any SIBO bacteria and causes them to produce more methane and hydrogen than they normally would.

Over a period of about two or three hours, I collect breath samples from the patient to measure the levels of these gases. Elevated levels indicate bacterial overgrowth in the small intestine.

If SIBO is present and severe, I may need to prescribe an antibiotic such as Xifaxan or Neomycin. More often, though, I prescribe an herbal combination that helps your body deal with the overgrowth in a more subtle way. It takes more time than antibiotics, but it limits the side effects.

As a functional medicine physician practicing in a concierge model, I have both the time and the freedom to thoroughly discuss each patient’s symptoms and use targeted testing to find the root cause. I can then prioritize what needs to be treated urgently versus what can be addressed through dietary and lifestyle modifications.

What to Do if You Suspect SIBO Symptoms

If you’re reading this and recognizing SIBO symptoms in yourself, you might be wondering what to do next.

First, if your symptoms are severe enough that weight loss or weakness (or a red flag symptom) has occurred, it’s time to seek medical help. Don’t wait.

If your symptoms are relatively minor, you might try an elimination diet to see if it makes a difference. One of the best strategies is trying a low-FODMAP diet. Pay attention to whether reducing or removing high-FODMAP foods from your diet improves your symptoms. If it does, you have a clue that you’re dealing with SIBO and can seek help accordingly.

SIBO is a chronic disease process that’s easily overlooked, but it’s also easy to treat when properly identified. So don’t hesitate to bring up your concerns with your physician so we can evaluate your symptoms and take appropriate measures, including SIBO testing if warranted.

Your gut is trying to tell you something. Make sure you (and your doctor) are listening.