Why Do I Feel Bloated After Eating? 3 Common Causes
You may look pregnant after a meal, but you know you’re not. Whether you feel embarrassed or you're able to joke about it, eventually you just want to feel comfortable in zipped pants.
What Causes Bloating?
Bloating is a common issue affecting women at any age, and there are a number of possible causes. Some are more serious, and need to be pushed for further medical investigation. These include cancerous and non-cancerous growths of the digestive and reproductive systems. However other causes, while still frustrating, are not taken seriously and tend to be overlooked by medical professionals.
The good news is that there are many options for investigating and treating bloating. Here are 3 common causes of bloating your doctor probably won’t tell you about. Read on to learn about symptoms, diagnosis and how they can be treated with good outcomes.
1.Small Intestinal Bacterial Overgrowth (SIBO)
While the large intestine houses a large amount of bacteria, the same should not be the case for our small intestine. Bacteria in our large intestine feed on undigested fibres and carbohydrates. The small intestine on the other hand is where we break down foods and absorb nutrients into our bodies. When bacteria overpopulate the small intestine they feed on these foods and produce large amounts of gas. This causes bloating and discomfort and interferes with the normal digestion and nutrient absorption (1).
What are the Symptoms?
Small intestinal bacterial overgrowth (SIBO) can cause symptoms such as bloating, discomfort, wind pain, reflux and nausea. Other signs might include nutrient deficiencies (e.g. vitamin B12, iron) despite adequate intake, food intolerances, restless legs, fatigue, poor sleep and constipation or diarrhea. In addition to bacteria, bloating can be caused by other microbes in the small intestine. These include methanogens (SIMO) or fungi (SIFO) such as yeast or mould.
Testing for SIBO
The gold standard for diagnosincg small intestinal overgrowths involves taking a microbial sample (aspirate culture) directly from the small intestine. This downside is that this test is not widely available. Fortunately small intestinal overgrowths can also be diagnosed via a SIBO breath test which is widely available and non-invasive. To date no specific test exists for diagnosing SIFO, however a diagnosis can be made through a combination of clinical assessment and functional tests.
Treatment for SIBO
Treatment involves reducing the growth of microbes in the small intestine and restoring balance to the gut microbiome. Treating the underlying causes of the overgrowth is also an important step. This can mean addressing factors such as poor digestion, thyroid conditions, stress and adhesions from previous abdominal surgeries.
2.FODMAP Intolerance
FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. Yes that is a mouthful! FODMAPs are types of carbohydrates found in food that cause bloating and digestive distress for some people. Lactose and fructose intolerance are good examples of this.
FODMAP intolerance can be driven by deficiencies in digestive enzymes, malabsorption issues and by overgrowths of bacteria in the small intestine. FODMAPs are prebiotic foods for gut bacteria. When bacteria breakdown these carbohydrates they produce lots of gas which can lead to bloating and discomfort. High FODMAP foods that commonly trigger bloating include milk, apples, pears, wheat bran, onions, garlic and cauliflower.
What are the Symptoms?
Symptoms of FODMAP intolerance include a range of digestive symptoms commonly associated with Irritable bowel syndrome (IBS). Bloating is the most common symptoms, but others include abdominal pain, flatulence, trapped wind, heartburn, nausea, diarrhea and constipation (2). Fructose malabsorption can also compromise tryptophan levels, a key precursor for the mood regulating brain chemical serotonin (3). This means possible changes in mood and anxiety levels.
Testing for FODMAP intolerance
FODMAP intolerance is diagnosed via a FODMAP elimination diet and reintroduction trial. People with bloating and other IBS symptoms often make the mistake of adopting a low FODMAP diet as a long term solution for their symptoms. However it is important to understand that the low FODMAP diet is meant to be used as an elimination diet only. As an elimination diet it helps to discern which FODMAPs are problematic for an individual and what level of intake of that FODMAP can be tolerated.
This is an important point. Not everyone who is FODMAP sensitive will be sensitive to all types of FODMAPs. This means that following the diet without reintroducing and testing different types of FODMAPS after a few weeks of elimination, can lead to avoiding foods unnecessarily. Since FODMAPs provide important fuel for gut bacteria this can have detrimental effects on the gut microbiome in the long-term.
Treatment for FODMAP Intolerance
Fortunately many people are able to slowly reintroduce FODMAPs and rebuild tolerance to them over a period of time. This process requires patience and can be difficult to navigate alone, so is best attempted with the support of a knowledgeable nutritionist or dietician. Underlying causes of FODMAP intolerance, such as SIBO, should also be clinically assessed and ruled out. Many diagnosed with fructose intolerance for example, have resumed normal tolerance after treating an underlying bacterial overgrowth.
3. Food Hypersensitivity
If you’re confused about the difference between food allergies and food intolerances, you’re not alone. These terms are often used interchangeably, creating a lot of confusion. However when it comes to pinpointing what is causing symptoms like bloating, it is important to understand the difference. While food intolerances such as “lactose intolerance” are caused by digestive issues, food hypersensitivities like allergies, are driven by an immune response (4). These food hypersensitivities are a common cause bloating after eating.
What are the Symptoms?
Technically there are 4 types of food hypersensitivities. Type 1 are the classic food allergies. These food reactions are driven by IgE antibodies and symptoms can be rapid and severe including hives, swelling, edema and anaphylaxis. While IgE food allergies can cause digestive distress, it’s the other 3 types of food hypersensitivity that are most likely to cause bloating.
These other food hypersensitivities involve immune responses that can be more delayed, and therefore more difficult to pin point than classic food allergies. While allergic food reactions occur within seconds and minutes, symptoms of food hypersensitivity can take hours or even days to appear. Though reactions can affect any part of the body, gastrointestinal symptoms such as bloating and pain, are common. A telltale complaint of those with these food hypersensitivities is that they wake up feeling bloated, and “everything” seems to make them bloat.
Testing for Food Hypersensitivity
While classic food allergies can be diagnosed through skin prick testing and blood tests, diagnosing food hypersensitivities is more complicated This is due to their delayed response and the number of possible immune pathways to rule out.
Food hypersensitivity tests include IgG, IgA and IgM antibody tests, complement testing and the ALCAT test which measures changes in leukocytes. These tests can be more expensive than allergy testing and more difficult to access and interpret. For this reason elimination diets can be helpful. Elimination diet diagnosis will involve following a low-reactive diet for a period of time until symptoms, such as bloating, subside. Foods are then reintroduced one-at-a-time and any symptoms are noted and recorded.
Treatment for Food Hypersensitivity
The first step in treating food hypersensitivities is pinpointing which foods are causing reactions. While some food hypersensitivities are best eliminated in the long-term, identifying and addressing the underlying drivers of food reactions can go a long way to rebuilding food tolerance. This treatment process will usually involve a health assessment to identify drivers of food reactivity.
Once food hypersensitivities have been identified, a period of elimination, while supporting immune and digestive health, can help to restore food tolerance. As foods are reintroduced it is important to establish the tolerance level (i.e. what quantity of the food can be tolerated). A rotation diet, where certain foods are eaten at set intervals, is often useful to prevent overexposure and relapse of food hypersensitivities and to rebuild tolerance over time. Other therapies that may be useful include food desensitisation techniques such as low dose immunotherapy (LDI).
Need help with bloating?
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References
1.Gasbarrini, A., Lauritano, E.C., Gabrielli, M., Scarpellini, E., Lupascu, A., Ojetti, V., & Gasbarrini, G. (2007). Small intestinal bacterial overgrowth: diagnosis and treatment. Digestive diseases, 25(3), 237-240. https://karger.com/ddi/article/25/3/237/95760/Small-Intestinal-Bacterial-Overgrowth-Diagnosis
2.Wong, W. M. (2016). Restriction of FODMAP in the management of bloating in irritable bowel syndrome. Singapore medical journal, 57(9), 476. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5027396/
3.Ledochowski, M., Widner, B., Murr, C., Sperner-Unterweger, B., & Fuchs, D. (2001). Fructose malabsorption is associated with decreased plasma tryptophan. Scandinavian journal of gastroenterology, 36(4), 367-371. https://www.tandfonline.com/doi/abs/10.1080/00365520117856
4.Chandra, R. K. (2002). Food hypersensitivity and allergic diseases. European Journal of Clinical Nutrition, 56(3), S54-S56. https://www.nature.com/articles/1601487