- SIBO is a digestive condition caused by an overgrowth of bacteria in the small intestine.
- Symptoms of SIBO vary from person to person but can include bloating, gas, abdominal pain, and diarrhea.
- Differentiating between SIBO and other digestive disorders is essential for proper diagnosis and treatment.
Small intestinal bacterial overgrowth (SIBO) is a condition caused by excessive bacteria in the small intestine. SIBO can cause many of the same uncomfortable and sometimes debilitating symptoms as other digestive health conditions, making it challenging to differentiate between them. It's estimated that up to 78% of people diagnosed with irritable bowel syndrome (IBS) have SIBO.
Getting the proper diagnosis and root cause of your symptoms is an essential first step to feeling better. If you have digestive symptoms without a diagnosis, a visit to your healthcare provider is always recommended. But understanding risk factors and symptoms can help you prepare for your appointment.
In this article, you'll learn more about why SIBO happens and answer 8 questions as a quick self-assessment to determine if SIBO might be the reason for your symptoms.
Diet plays a significant role in supporting SIBO symptoms and healing. If you have SIBO, consider booking a virtual appointment with a registered dietitian. Nourish offers personalized nutrition counseling and accepts the most popular insurance carriers.
What is SIBO?
Small intestinal bacterial overgrowth (SIBO) occurs when bacteria that usually live in the large intestine move into the small intestine.
There are two main types of SIBO: hydrogen dominant or methane dominant (now called intestinal methane overgrowth since methanogens aren't technically bacteria). Both are named for the type of gas produced when carbohydrates are fermented in the small intestine.
SIBO is usually diagnosed using a breath test that measures hydrogen and methane produced by bacteria in the small intestine. These tests involve drinking a glucose or lactulose solution and breathing into a specialized bag at timed intervals. The SIBO test isn't perfect and can lead to false negatives, but they are currently the best available non-invasive methods for diagnosing SIBO.
Risk Factors for SIBO
The potential causes of SIBO are complex, but anything that impairs the body's natural protective mechanisms that keep bacteria where it's supposed to be can increase the risk. Under normal conditions, cleansing waves called the migrating motor complex help keep food and bacteria moving down the digestive tract. Alterations in the process can increase the risk of SIBO.
Risk factors linked to SIBO include:
- Medication that slows down the GI tract, like opioids.
- Medical conditions that impair gastric motility (how things move down the digestive tract), like neuropathy from diabetes.
- Low stomach acid.
- Surgical alterations impacting the GI tract.
- Digestive health conditions like diverticulosis or inflammatory bowel disease.
8 Questions to Help Determine if You Have SIBO
The following questions aren't a replacement for a medical diagnosis but can be used to help assess if you might have SIBO.
Question 1: Do You Experience Gas or Bloating After Eating?
Feeling bloated or uncomfortable after eating a big meal isn't abnormal, but if this happens regularly after eating a normal-sized meal or small snacks, it could indicate something else.
When bacteria ferment fiber in your small intestine, the resulting hydrogen, methane, and carbon dioxide can cause significant bloating and discomfort. People with SIBO often notice they feel best when first waking up in the morning. Still, the bloating gets progressively worse throughout the day.
Give yourself one point if you experience gas and bloating consistently after meals or throughout the day.
Question 2: Do You Experience Abdominal Pain or Cramping?
Abdominal pain and cramping are common symptoms of SIBO caused by gas or inflammation in the GI tract. SIBO isn't the only reason for abdominal pain or cramping, so this symptom alone isn't necessarily a sign that you have it. Still, if you experience pain that worsens after meals and improves when fasting, it could be a sign of SIBO.
Give yourself one point if you experience stomach pain or cramping regularly.
Question 3: Do You Have Diarrhea, Constipation, or Both?
Diarrhea and constipation can be attributed to many digestive disorders, including SIBO. Diarrhea occurs most often with hydrogen-dominant SIBO, while constipation is more likely to occur with methane-dominant SIBO (and it's possible to also have both).
Irritable bowel syndrome also may cause diarrhea or constipation, making it difficult to differentiate between them. If you have alternating diarrhea and constipation, and you've tried treatments for IBS without success, it's worth considering SIBO as a potential cause.
Give yourself one point if you experience diarrhea, constipation, or both at least a couple times per week.
Question 4: Have You Experienced Unintended Weight Loss?
In severe cases of SIBO, malabsorption can lead to unintentional weight loss. People with SIBO may also restrict food intake to remove food that may trigger symptoms or because they just don't feel well enough to eat. These factors can lead to unintentional weight loss, especially with chronic diarrhea.
Give yourself two points if you have experienced unintentional weight loss or unexplained vitamin deficiencies. Note: any unintended weight loss warrants an immediate appointment with your healthcare practitioner.
Question 5: Do Antibiotics Temporarily Improve Your Symptoms?
SIBO is often treated with specific antibiotics used to kill bacterial overgrowth. Even when different antibiotics are used, some people may experience symptom relief even if the medication is for an unrelated condition.
Symptoms usually return soon after (sometimes even worse because of the loss of beneficial species of bacteria) because even if bacteria are temporarily reduced, antibiotics don't address why the bacterial overgrowth occurred in the first place. For example, bacteria will eventually repopulate if someone has gastric motility problems. SIBO may return because antibiotics don't address the root cause.
Give yourself two points if you've noticed temporary relief after taking antibiotics for an unrelated condition.
Question 6: Have You Been Diagnosed with Another Digestive Disorder?
Digestive diseases such as celiac, Crohn's disease, and pancreatitis are all linked to an increased risk of SIBO. For example, some research suggests that people with IBD (like Crohn’s disease) are nine times more likely to have SIBO compared to those without.
Digestive disorders can cause inflammation in the gut, reduce enzymes that help limit bacterial growth, or lead to surgery that could impair the normal functioning of the GI tract—all contributing to the risk of SIBO.
Give yourself one point for this question if you have been diagnosed with another digestive disorder.
Question 7: Have You Been Diagnosed with an Autoimmune Disease?
The connection between autoimmunity and the gut is complex, but it is becoming increasingly clear that there's a direct link between them. More research is needed to completely understand the connection, but inflammation in the gut may be a risk factor for developing autoimmune conditions like Hashimoto's thyroiditis.
Give yourself one point if you've been diagnosed with an autoimmune disease.
Question 8: Do you have a history of using PPIs?
Proton pump inhibitors (PPIs) are medications often prescribed to treat gastroesophageal reflux disease (GERD) or what many people call acid reflux.
Stomach acid acts as a protective mechanism by killing bacteria and other pathogens that enter our gut from the environment. When PPIs are taken for extended periods, they can reduce stomach acid too much and may increase the risk of SIBO.
Give yourself two points if you have a history of using PPIs.
Interpreting Your SIBO Quiz Results
If you answered yes to any of these questions, it's worth exploring the possibility of SIBO. A higher score may indicate a higher risk of SIBO, especially if you have any digestive symptoms in questions 1 through 3 and answered yes to questions 4 through 8.
Understanding the risk factors and common symptoms of SIBO can increase the likelihood of finding the correct diagnosis. Treatment for SIBO may include medications, supplements, diet, and lifestyle changes.
You can use your answers to the quiz as a guide to share with your healthcare practitioner so you can get the proper care to feel good in your body again.
Managing SIBO with an RD
Nutrition can support your symptoms and ensure you get the nutrients your body needs. A registered dietitian (RD) can help you develop a personalized plan for your body while focusing on strategies to optimize gut health before, during, and after SIBO treatment. Connect with an RD today.
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