SIBO Symptoms: Bloating and How to Relieve It

Content

1. Natural Gas Production in the Gut
2. Bloating in SIBO
3. Bloating in IBS
4. Causes of Excessive Gas Production
4.1 Eating Habits
4.2 Stress
4.3 Organic Causes
4.4 Food Intolerances / FODMAP Sensitivity
4.5 Hormonal Imbalances and Other Factors
4.6 Gut Microbiota
5.How to reduce Bloating

Everyone knows the feeling—your belly is so bloated, it looks like you’re pregnant. But what actually causes bloating? And why is this symptom so common in SIBO and irritable bowel syndrome (IBS)?

1. Natural Gas Production in the Gut

As part of normal digestion, bacteria in the gut produce gases. When food residues are broken down, nitrogen, oxygen, methane, hydrogen, and carbon dioxide are released as byproducts. We only notice this process when an unusual amount of gas builds up. Excess gas can put pressure on other organs, leading to symptoms like bloating, abdominal pain, or even chest discomfort. In some cases, it may also cause back pain.

Normally, the gut contains about 200 ml of gas (1), and we produce approximately 2.5 liters of gas daily. However, most of this gas is not expelled through burping or flatulence—it is absorbed into the bloodstream and exhaled through the lungs. This is also how the breath test for diagnosis of SIBO works: Bacteria produce certain gases, which will be absorbed into the blood and then exhaled through the lung. Those gases in the exhaled air can be measured and used to diagnose SIBO.

2. Bloating in SIBO

SIBO stands for “Small Intestinal Bacterial Overgrowth,” a condition where excessive bacteria accumulate in the small intestine. Unlike the colon, the small intestine is usually sparsely populated with bacteria. When bacteria overgrow in the wrong place, they overwhelm the small intestine, which struggles to manage the large amounts of gas and toxins they produce. This leads to symptoms like abdominal pain, bloating, diarrhea, constipation, belching, fullness, and heartburn. Some people also report fatigue and difficulty concentrating.

Bloating is a classic symptom of SIBO (3). Symptoms typically appear within 120 minutes after eating and improve during fasting periods. Gas doesn’t always escape as flatulence because it forms in the middle of the digestive tract and may not move out quickly. If SIBO affects the upper small intestine, it can cause excessive burping.

3. Bloating in IBS

Bloating is a common complaint among IBS patients (2). Besides increased gas production, IBS sufferers tend to be more sensitive to the gas in their intestines. They feel bloated earlier, which can lead to discomfort and pain. However, bloating is just one of many IBS symptoms. Many people with IBS also experience changes in bowel habits, such as diarrhea or constipation.

4. Causes of Excessive Gas Production

There are many causes of bloating. Factors such as eating habits, stress, underlying medical conditions, food intolerances, and hormonal imbalances can all contribute. If bloating is persistent, it’s important to seek medical evaluation.

4.1 Eating Habits

In addition to normal gas production, swallowing air while eating can contribute to bloating. Eating too quickly can cause excessive air intake, a condition known as aerophagia. This can lead to bloating, burping, fullness, or abdominal pain after meals.

4.2 Stress

Fast eating is often linked to stress. However, stress itself can directly contribute to bloating. It activates the sympathetic nervous system, which can affect gut motility. While stress may cause diarrhea in some people, it leads to constipation and bloating in others.

4.3 Organic Causes

Bloating can also have organic causes, which is why persistent symptoms should always be evaluated by a doctor. Possible underlying conditions include pancreatic insufficiency, gastritis, SIBO and thyroid disorders.

4.4 Food Intolerances / FODMAP Sensitivity

Certain foods and beverages can contribute to bloating, depending on individual tolerance levels. Common triggers include legumes, cabbage, onions, garlic, alcohol, coffee, and carbonated or sugary drinks.
Food intolerances are another major cause of bloating. For example, in lactose intolerance, insufficient lactase enzyme production prevents proper digestion of lactose, leading to bacterial fermentation and excess gas. Similarly, gluten, fructose, and sorbitol intolerances can cause digestive distress, as these substances are poorly absorbed.

4.5 Hormonal Imbalances and Other Factors

Other factors that may contribute to IBS-related symptoms include hormonal imbalances, sedentary lifestyles, as well as psychological stress.

4.6 Gut Microbiota

The bacteria living in our gut play an essential role in digestion. They produce short-chain fatty acids that nourish the gut lining, regulate pain perception, and influence gut motility, ensuring proper stool formation. Depending on the composition of gut bacteria, they can either promote or prevent digestive disorders. Research now suggests that the gut microbiome plays a key role in IBS development.

5.How to reduce Bloating

Managing bloating and excessive gas can be challenging. However, by making small changes in food preparation and lifestyle, it’s possible to alleviate discomfort.
Here are some practical tips:
1. Soak legumes for at least 12 hours before cooking and change the soaking water up to three times.
2. Use garlic or onion-infused oil instead of fresh garlic or onions.
3. Opt for steamed vegetables over raw ones.
4.Incorporate digestion-friendly spices like ginger, turmeric, fennel, cumin, anise, and caraway (4).
5.Engage in regular physical activity to stimulate digestion, but avoid extreme exercise.
6.Try abdominal massages in a clockwise direction to relieve bloating.

It’s important to identify which strategies work best for your body. However, if symptoms persist, consulting a doctor is recommended.

References

1. Scaldaferri F, Nardone O, Lopetuso LR, Petito V, Bibbò S, Laterza L, Gerardi V, Bruno G, Scoleri I, Diroma A, Sgambato A, Gaetani E, Cammarota G, Gasbarrini A. Intestinal gas production and gastrointestinal symptoms: from pathogenesis to clinical implication. Eur Rev Med Pharmacol Sci. 2013;17 Suppl 2:2-10. PMID: 24443061.
2. Borghini R, Donato G, Alvaro D, Picarelli A. New insights in IBS-like disorders: Pandora’s box has been opened; a review. Gastroenterol Hepatol Bed Bench. 2017 Spring;10(2):79-89. PMID: 28702130; PMCID: PMC5495893.
3. Bures J, Cyrany J, Kohoutova D, Förstl M, Rejchrt S, Kvetina J, Vorisek V, Kopacova M. Small intestinal bacterial overgrowth syndrome. World J Gastroenterol. 2010 Jun 28;16(24):2978-90. doi: 10.3748/wjg.v16.i24.2978. PMID: 20572300; PMCID: PMC2890937.
4. Platel K, Srinivasan K. Digestive stimulant action of spices: a myth or reality? Indian J Med Res. 2004 May;119(5):167-79. PMID: 15218978.