What are the causes and management options for abdominal bloating?

Causes of Abdominal Bloating

Abdominal bloating is primarily caused by functional gastrointestinal disorders, motility issues, and visceral hypersensitivity, with specific conditions including irritable bowel syndrome, small intestinal bacterial overgrowth, celiac disease, and functional dyspepsia requiring targeted diagnostic and treatment approaches. 1

Common Causes of Abdominal Bloating

Functional Gastrointestinal Disorders

• Irritable Bowel Syndrome (IBS) - commonly presents with bloating alongside altered bowel habits
• Functional Dyspepsia (FD) - upper abdominal bloating and fullness
• Functional constipation - bloating associated with infrequent bowel movements

Food-Related Causes

• FODMAP intolerance - fermentable oligosaccharides, disaccharides, monosaccharides, and polyols
• Celiac disease and non-celiac gluten sensitivity (NCGS) 1
• Fructan sensitivity - often mistaken for gluten sensitivity

Microbial Imbalances

• Small Intestinal Bacterial Overgrowth (SIBO) - particularly in patients with:
  • Chronic watery diarrhea
  • Malnutrition and weight loss
  • Systemic diseases causing dysmotility (e.g., Parkinson's disease, cystic fibrosis) 1

Motility Disorders

• Gastroparesis - delayed gastric emptying
• Pelvic floor disorders - including dyssynergic defecation
• Abdominophrenic dyssynergia (APD) - abnormal diaphragmatic function 1

Other Important Causes

• Ovarian cancer - particularly in women over 50 years (important not to miss) 1
• Chronic pancreatitis - bloating with pain despite enzyme replacement 1
• Helicobacter pylori infection - especially in high-prevalence regions 1

Diagnostic Approach

Initial Evaluation

• Assess for alarm symptoms:
  • Weight loss >10%
  • GI bleeding
  • Vomiting
  • Family history of inflammatory bowel disease
  • Recent worsening of nausea or pain 1

Basic Testing

• Complete blood count and comprehensive metabolic panel
• Abdominal imaging (X-ray, ultrasound, CT/MRI) to exclude structural abnormalities
• Upper endoscopy for patients >40 years with dyspeptic symptoms 1

Specialized Testing Based on Suspicion

• For SIBO: Hydrogen-based breath testing with glucose or lactulose
• For celiac disease: Tissue transglutaminase IgA and IgA levels
• For motility disorders: Consider gastric scintigraphy or wireless motility capsule studies in patients with severe nausea/vomiting 1
• For anorectal disorders: Anorectal manometry for suspected pelvic floor dysfunction 1

Management Approaches

Dietary Interventions

• Low-FODMAP diet - provides symptom improvement in >80% of patients at 1 month 2
  • Should be implemented under guidance of a trained dietitian
  • Include planned reintroduction phase to avoid negative impacts on gut microbiome
• Reduce gas-producing foods (beans, lentils, cruciferous vegetables)
• Avoid fatty foods, spicy foods, chocolate, caffeine, and alcohol 2

Pharmacological Treatments

• For gas and bloating:
  • Simethicone - reduces gas bubbles 2
  • Rifaximin - for documented SIBO 2
• For constipation-associated bloating:
  • Secretagogues (lubiprostone, linaclotide, plecanatide) 2, 3
  • Lubiprostone has shown efficacy in IBS-C with bloating as a symptom 3
• For visceral hypersensitivity:
  • Tricyclic antidepressants (e.g., amitriptyline 10-50mg)
  • Serotonin-norepinephrine reuptake inhibitors (duloxetine, venlafaxine)
  • Pregabalin - shown improvements in bloating in IBS patients 2
• For belching-predominant symptoms:
  • Baclofen (5-10mg TID) may be beneficial 2

Behavioral Therapies

• Diaphragmatic breathing exercises - particularly effective for abdominophrenic dyssynergia 2
• Anorectal biofeedback therapy - effective when bloating is associated with dyssynergic defecation (54% response rate) 2
• Cognitive behavioral therapy and gut-directed hypnotherapy 2

Common Pitfalls to Avoid

• Overlooking ovarian cancer in women >50 years with bloating 1
• Missing pelvic floor dysfunction as a cause of bloating 2
• Empiric use of probiotics without clear indication 2
• Inadequate implementation of dietary interventions like low-FODMAP diet 2
• Overlooking psychological components (anxiety, stress) that contribute to symptoms 2
• Failing to distinguish between functional dyspepsia and gastroparesis, which often present similarly 1

By systematically evaluating for these causes and implementing targeted treatments, most patients with abdominal bloating can experience significant symptom improvement.