Why Do You Keep Getting Abdominal Gas? SIBO vs IBS | Bloating

1. Gas and Abdominal Bloating: Why Have They Become Such Common Symptoms?

Lately, there's a phrase I hear most often in my clinic: “Doctor, my stomach gets full just after eating. But my colon is normal, so why is this happening?” In most cases, neither gastroscopy nor colonoscopy reveals any particular abnormalities. However, from the patient's perspective, it's clearly uncomfortable, to the point of disrupting daily life.
Especially when post-meal abdominal bloating, belching, borborygmi, and gas production recur, it's not simply a matter of indigestion. While we commonly refer to these as 'functional dyspepsia' or 'irritable bowel syndrome,' there are often more complex and subtle pathological conditions hidden within. Representative examples of these are IBS and SIBO, which we will discuss today.

2. IBS and SIBO: Similar Symptoms, Different Diseases

The symptoms experienced by patients in both conditions largely overlap.

• Severe abdominal bloating after meals
• Gas buildup and frequent belching
• Gurgling in the intestines or an unpleasant sensation of movement
• Loose stools, constipation, or alternating diarrhea and constipation

However, because endoscopy, X-rays, ultrasound... no matter where we look, no findings are caught, they are simply classified as 'functional' conditions, deemed 'not organic diseases.' But their starting points are different. IBS is a dysregulation of intestinal function itself, while SIBO is an overgrowth of bacteria in the small intestine. In other words, neither has a 'visible disease in the intestines,' but their mechanisms of action are completely different. Therefore, the treatment approaches also go in opposite directions.

3. IBS – A Sensitive Gut, an Overreactive Brain

IBS is centered on abnormalities in sensation and motility, and an imbalance in the autonomic nervous system, rather than structural problems within the intestine itself. The speed at which food passes through the intestines becomes either too fast or too slow, and intestinal stimuli that would normally go unnoticed are excessively perceived as 'discomfort.' Simply put, intestinal movements that are normal for others become a source of significant discomfort and pain for IBS patients. This is not just an intestinal problem; it's also a problem with the gut-brain connection – the so-called gut-brain axis. Stress, lack of sleep, and autonomic nervous system dysfunction are deeply interconnected.

4. SIBO – When Bacteria Overgrow in the Gut

SIBO, on the other hand, is a much more mechanical and microbial disease. Normally, the small intestine is a space with very few bacteria; however, if many bacteria, like those in the large intestine, proliferate there, problems arise. This is because these bacteria ferment the food we eat, producing enormous amounts of gas. The result?

• Extreme bloating within 30 minutes after a meal
• Belching, increased intra-abdominal pressure
• Even nausea and abdominal discomfort due to excessive gas production

Since SIBO is a condition where intra-abdominal pressure actually increases, the bloating sensation experienced by the body is a physical phenomenon, not just a 'feeling'.

5. So, Symptoms Are Similar, But Treatment Differs

This is where the confusion begins. Patients complain of the same 'gas' and 'bloating,' but if dietary therapy is applied without understanding the underlying mechanism, it can actually worsen the condition. For IBS, a FODMAP diet is effective. Reducing the intake of fermentable carbohydrates decreases intestinal hypersensitivity. Stress management, abdominal breathing, and stabilization of bowel movements are key to treatment. For SIBO, FODMAP alone is insufficient. Strategies like the Specific Carbohydrate Diet (SCD) or the Bi-phasic Diet, which completely cut off the bacteria's food supply, are necessary. In some cases, the bacterial count must be directly reduced with antibiotics or antimicrobial herbal medicine.

6. What's Truly Confusing is That Both Can Occur Simultaneously

In clinical practice, such cases are frequent.

• Individuals diagnosed with IBS who diligently followed a FODMAP diet but saw no improvement
• Individuals who received antibiotic treatment but experienced recurrence and increased gut sensitivity
• Cases where SIBO worsens in stressful situations

In other words, intestinal damage or irritation caused by SIBO can also trigger autonomic hypersensitivity reactions, similar to IBS. And the reverse is also possible. In such cases, a step-by-step approach is necessary. If SIBO is suspected, first, bacterial control, followed by dietary adjustments and gut barrier restoration, and finally, stabilization of the autonomic nervous system and restoration of gastrointestinal function. Only by establishing such a sequence and priorities can complex cases begin to be resolved.

7. More Important Than the Name is the 'Mechanism of the Disease'

Ultimately, the diagnosis itself is not what's important. What's most important is understanding how those symptoms are functioning, that is, 'how the disease is playing out within that individual.' Even with the same sensation of bloating, some may experience it due to gas produced by bacteria, while others may feel it because of hypersensitive nerves. Without knowing that difference, even the best treatment is likely to miss its mark. So, if your abdominal bloating persists, gas builds up daily, and you continue to experience uncomfortable days due to indigestion, it might not be something that can simply be resolved with gastrointestinal medication.

#IBS #SIBO #AbdominalBloating