Bloating is a frustrating, yet common, issue affecting up to 15-30% of people on a weekly basis. While some amount of bloating can be normal, it becomes abnormal when it's severe, painful, and does not resolve in a reasonable timeframe. Much of the frustration with bloating is the challenge in treating it. This is because there are a handful of potential underlying causes, and not all of them are specific to the digestive tract. To find effective treatment, proper diagnosis is critical.
This article will cover 10 surprising causes of bloating that you may not have considered before.
What Causes Bloating?
Before jumping into the causes of bloating, let's break down what the two main types of bloating are and how they develop.
Gaseous Bloating
All carbohydrates (vegetables, fruits, breads, pasta, etc.) are made up of many sugar molecules, such as lactose, fructose, and sucrose. These sugars are typically broken down in the small intestine by enzymes. The remaining carbohydrates that make it to the large intestine are fermented to feed the microbiome and provide beneficial byproducts like short-chain fatty acids (important for metabolic health!). Fermentation of these sugars results in gas production, which is ultimately breathed out or passed as gas. However, bacteria in the small intestine can also ferment the carbohydrates. When the sugars aren't broken down properly in the small intestine, there is an excess of fermentation happening in the small and large intestine, and this excess gas causes stretching of the intestines, pain and bloating.
Fluid Retention Bloating
Bloating that is not associated with gas is usually related to fluid retention. Fluid retention refers to water building up in the body. While our bodies are naturally high in water, too much can cause bloating and edema (the medical term for excess water retention). Some of the more common ways this can happen are excessive salt intake, hormonal changes, or can be related to more serious conditions like liver, kidney and heart disease.
Reminder - If you are ever experiencing significant changes to your health, always consult a doctor!
Causes of Bloating
1. Food Sensitivities and Intolerances
Food sensitivities and intolerances are common causes of gaseous bloating and are often missed or can be difficult to identify. Unlike food allergies, there aren't great tests that identify food sensitivities. Blood tests can be a helpful tool, though the most effective way to determine if sensitivities and intolerances are present is to do an elimination diet.
Lactose intolerance is one of the most common food intolerances, affecting up to 70-90% of people depending on ethnicity (Scandinavian descent are least likely to be affected). Other common intolerances are to other carbohydrate sugars like fructose and sucrose. Common food sensitivities include sensitivities to gluten, egg, soy and corn. Food intolerances and sensitivities not only result in bloating, but also typically present with diarrhea, weight loss, abdominal pain, nausea and/or vomiting.
2. Celiac Disease
Celiac disease is a specific type of food intolerance to gluten that is autoimmune-mediated. There is an abnormal immune response that causes damage to the small intestine in response to gluten. The result is poor digestion and absorption, nutrient deficiencies, and symptoms like fatigue, brain fog and skin rashes. The abnormal digestion that results from Celiac disease creates gaseous bloating in a similar way to other food intolerances, and also presents with similar digestive symptoms like diarrhea and weight loss.
Unlike non-Celiac gluten sensitivity, Celiac disease causes true damage to the small intestine, so if you are concerned about Celiac disease, definitely consider testing with a doctor before making dietary changes. Once gluten has been removed from the diet, Celiac disease can be harder to diagnose.
3. Small Intestinal Bacterial Overgrowth (SIBO/IMO/SIFO)
Small intestinal bacterial overgrowth (SIBO), intestinal methanogen overgrowth (IMO), and small intestinal fungal overgrowth (SIFO) are all causes of gaseous bloating that are due to changes in the microbiome, otherwise known as dysbiosis. While there is a microbiome in the small intestine, the vast majority is found in the large intestine. When the amount of bacteria (or fungi) in the small intestine gets too high, the primary symptom is often significant bloating.
SIBO and IMO can be easily tested for with breath testing. SIFO, on the other hand, does not have an option for breath testing yet, and can only be definitively diagnosed by collecting a fluid sample from the small intestine (an invasive procedure). However, a trained professional may be able to diagnose SIFO clinically, meaning without testing, so you can still get treated.
4. Dysbiosis - Bacterial, Yeast/Fungal, Parasites
Dysbiosis refers to any imbalances of the microbiome, and is another cause of gaseous bloating. SIBO, IMO and SIFO are specific types of dysbiosis that occur in the small intestine, though there are also many other causes of dysbiosis that occur primarily in the large intestine.
The microbiome is made up of billions of microorganisms. When any of these organisms are out of balance, dysbiosis occurs. One of the more well-known types of dysbiosis is intestinal candidiasis (presence of Candida, a type of yeast) in the gut. Dysbiosis can occur when:
Bacteria, viruses, or yeast that are not supposed to be present are
There is too little or too much of bacteria, viruses or yeast that are expected to be there
Parasites are present
Dysbiosis can be tested for using comprehensive stool analysis, in which the composition of the microbiome is mapped out so imbalances can be identified, and targeted treatments can be developed.
5. H. pylori Infection and Hypochlorhydria
Dyspepsia is the primary symptom of gastroesophageal reflux disease (GERD), and includes both heartburn and indigestion. Typically GERD is caused by hypochlorhydria, or low stomach acid production, which in turn results in poor digestion and symptoms such as belching, discomfort with meals, and bloating. Bloating in this case is related to excess gas production, but can also be related to the sensation of fullness that is common with hypochlorhydria. Stomach acid is not only crucial for proper digestion, but it's also important in maintaining a healthy microbiome by killing ingested bacteria and preventing dysbiosis.
H. pylori is one of the causes of hypochlorhydria. This is a bacteria that commonly inhabits the stomach, and in many individuals does not cause problems. H. pylori secretes an enzyme that breaks down stomach acid, so too much H. pylori can mean too little stomach acid. Having low stomach acid due to other reasons also increases your risk of H. pylori.
Other causes of hypochlorhydria include advanced age, chronic stress, use of proton-pump inhibitors (PPIs) or acid blockers, hypothyroidism, SIBO and certain medications.
6. Exocrine Pancreatic Insufficiency (EPI)
Exocrine pancreatic insufficiency (EPI) is a condition characterized by low digestive enzyme secretion. Digestive enzymes are made by and secreted from the pancreas and are responsible for the breakdown of carbohydrates, fats and proteins in the small intestine. When digestive enzymes are low, food is not properly broken down and cannot be absorbed. This results in bloating, and typically diarrhea as well.
EPI is most commonly caused by acute or chronic pancreatitis, which is typically related to alcohol overconsumption, and cystic fibrosis. Other causes include advanced age, chronic stress, Celiac disease, inflammatory bowel disease (IBD), diabetes and food sensitivities.
7. Hypothyroidism
Hypothyroidism is a condition in which thyroid hormones are low. As thyroid hormones play a vital role in metabolism, hypothyroidism results in slowed metabolism and slowed digestion. One role of thyroid hormone is regulating gut motility. The slowed motility that comes with hypothyroidism impairs digestion and causes constipation, both of which can result in bloating.
Another way in which hypothyroidism can cause bloating is via fluid retention. This is the type of bloating that is not caused by increased gases, but instead by increased salt and water retention. Bloating from fluid retention usually shows up as weight gain.
8. Diabetes & Insulin Resistance
Diabetes and insulin resistance are similar conditions that typically occur together, though don't have to. Diabetes involves the chronic elevation of blood sugar and insulin resistance is when the body responds poorly to insulin. Poorly managed diabetes can lead to damage to nerves, including the nerves of the digestive tract.
Gastroparesis, paralysis of the stomach related to nerve damage, is a complication of diabetes. With gastroparesis, the movement of the stomach slows and becomes weaker, causing food to sit in the stomach too long. The stomach is where food is mechanically broken down, so digestion is incomplete with gastroparesis, ultimately resulting in bloating.
9. Estrogen Dominance
Estrogen dominance is how it sounds - excess estrogen function. The best way to think about this is the ratio between estrogen and progesterone. Estrogen dominance can either be due to elevated estrogen, or normal estrogen with low progesterone (resulting in relatively high estrogen).
Estrogen dominance can cause many symptoms such as headaches, irregular and/or painful periods, fatigue, brain fog, and bloating. The bloating associated with estrogen dominance is similar to hypothyroidism, due to fluid retention as opposed to excess gas production. Bloating related to estrogen dominance tends to worsen before or during menstruation.
10. Poor Eating Habits
Aside from what you eat, how you eat can also contributing to digestive issues. Some poor eating habits include eating too quickly, eating distracted, not chewing completely or eating too large of meals. Eating quickly can cause air to be swallowed. Not chewing completely and swallowing larger parts can make it harder to break everything down, leaving more to be fermented and more gas produced. Eating too much can cause the stomach to stretch, creating a sensation of bloating. Eating distracted can cause any of the previous poor eating habits to occur.
Conclusion
Bloating can be caused by a variety of factors, many of which are often overlooked or misunderstood. From digestive imbalances like SIBO and dysbiosis to hormonal shifts and food sensitivities, pinpointing the root cause is essential for effective treatment. If you’re tired of dealing with persistent bloating and want personalized solutions, consider working with a naturopathic or functional doctor who can help guide you through testing, dietary changes, and targeted therapies.
Disclaimer
The information provided in this blog and throughout the website is intended for educational purposes only and should not be considered, or used as a substitute for, medical advice. The content is not meant to diagnose, treat, or cure any medical condition. This blog does not constitute the practice of any medical, nursing or other professional health care advice, diagnosis or treatment. Always consult with a qualified healthcare provider before making any changes to your health regimen or starting new treatments, and never disregard professional medical advice or delay seeking care because of something that you have read on this blog, website or in any linked materials. Your individual needs and circumstances should be evaluated by a medical professional to ensure safe and appropriate care. If you are experiencing a medical emergency, please call 911 or call for emergency medical help on the nearest telephone immediately.
References
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Cleveland Clinic. “Exocrine Pancreatic Insufficiency (EPI): Pancreatitis.” Accessed September 23, 2024. https://my.clevelandclinic.org/health/diseases/21577-exocrine-pancreatic-insufficiency-epi.
Lacy, Brian E., David Cangemi, and Maria Vazquez-Roque. “Management of Chronic Abdominal Distension and Bloating.” Clinical Gastroenterology and Hepatology 19, no. 2 (February 2021): 219-231.e1. https://doi.org/10.1016/j.cgh.2020.03.056.
Mari, Amir, Fadi Abu Backer, Mahmud Mahamid, Hana Amara, Dan Carter, Doron Boltin, and Ram Dickman. “Bloating and Abdominal Distension: Clinical Approach and Management.” Advances in Therapy 36, no. 5 (2019): 1075–84. https://doi.org/10.1007/s12325-019-00924-7.
Wilkinson, John M., Elizabeth W. Cozine, and Conor G. Loftus. “Gas, Bloating, and Belching: Approach to Evaluation and Management.” American Family Physician 99, no. 5 (March 1, 2019): 301–9.