What causes excessive gas?

Causes of Excessive Gas

Excessive gas is primarily caused by food intolerances, carbohydrate malabsorption, aerophagia (air swallowing), disorders of gut-brain interaction, and altered gut microbiota. 1, 2

Common Causes of Excessive Gas

Food-Related Causes

• Carbohydrate malabsorption:
  • Lactase deficiency (lactose intolerance)
  • Fructose malabsorption (found in 60% of patients with IBS)
  • Sucrase deficiency
  • FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols)
  • Artificial sweeteners (sugar alcohols like sorbitol) 1, 2

Air Swallowing (Aerophagia)

• Unconscious swallowing of air while eating, drinking, or talking
• Can be diagnosed when manometry shows influx of air into the esophagus with swallowing
• Results in intestinal gas accumulation visible on abdominal X-rays 1
• Often associated with anxiety and can lead to bloating rather than just belching 1, 3

Gastrointestinal Disorders

• Disorders of gut-brain interaction (DGBIs):
  • Irritable Bowel Syndrome (IBS)
  • Functional dyspepsia
  • Functional bloating and distention 1, 4
• Gastroesophageal reflux disease (GERD) - associated with belching in up to 50% of patients 1
• Gastroparesis - delayed gastric emptying 1
• Small intestinal bacterial overgrowth (SIBO) - excessive bacteria in small intestine 2

Belching-Specific Causes

• Supragastric belching - voluntary process where air enters esophagus and is rapidly expelled before reaching stomach
• Gastric belching - involuntary process involving transient relaxation of lower esophageal sphincter 1

Other Contributing Factors

• Visceral hypersensitivity - increased sensitivity to normal amounts of intestinal gas 4
• Impaired gas transit - abnormal movement of gas through the intestines 5, 4
• Abdominophrenic dyssynergia (APD) - abnormal diaphragm and abdominal muscle coordination 2
• Pelvic floor disorders - can contribute to gas retention 2

Diagnostic Considerations

When to Consider Specialized Testing

• For persistent symptoms despite initial management:
  • Hydrogen/methane breath testing - to evaluate for SIBO or carbohydrate malabsorption 2
  • High-resolution esophageal manometry with impedance monitoring - to differentiate types of belching 1, 2
  • Upper GI endoscopy - if symptoms persist >8 weeks despite therapy or alarm features present 2

Management Approaches

Dietary Modifications

• Trial elimination of gas-producing foods:
  • Beans, lentils, cruciferous vegetables
  • High-FODMAP foods
  • Lactose-containing products (if lactose intolerant)
  • Artificial sweeteners 1, 2, 5

Pharmacological Options

• Simethicone - reduces gas bubbles and provides relief from pressure and bloating 2, 6
• Enzyme supplements - such as alpha-galactosidase or lactase for specific intolerances 7
• Prokinetic agents - may help with gas transit in some patients 7, 8

Behavioral Therapies

• Diaphragmatic breathing exercises - particularly effective for abdominophrenic dyssynergia 2
• Cognitive behavioral therapy - helpful for associated anxiety and gas-related symptoms 2
• Biofeedback therapy - effective when bloating is associated with dyssynergic defecation 2

Key Pitfalls to Avoid

• Assuming all gas symptoms have the same cause
• Overlooking the role of anxiety and stress in exacerbating symptoms
• Prolonged restrictive diets without professional guidance
• Empiric use of probiotics without clear indication (not recommended by AGA for bloating treatment) 2
• Failing to distinguish between gas production and gas perception problems 3

By understanding the specific cause of excessive gas, targeted treatments can be implemented to provide effective symptom relief and improve quality of life.