How should I manage abdominal bloating?

Management of Abdominal Bloating

Start with a 2-week elimination diet to identify food intolerances, particularly focusing on FODMAPs and fructose, as this addresses the most common underlying cause and can achieve complete symptom resolution in 50% of patients at one year. 1, 2

Initial Diagnostic Approach

Identify the Pattern and Triggers

• Meal-triggered distention (during or immediately after eating) suggests abdominophrenic dyssynergia (APD), where the diaphragm paradoxically contracts while abdominal muscles relax, causing visible distention even without significant gas accumulation 2, 3

• Food-specific symptoms that improve with dietary restriction indicate food intolerances—fructose intolerance affects approximately 60% of patients with digestive disorders, compared to 51% for lactose intolerance 2, 4

• Constant bloating unrelated to specific foods or meals suggests small intestinal bacterial overgrowth (SIBO) or dysbiosis 3, 4

• Bloating with constipation and straining (even with soft stool), digital disimpaction, or splinting indicates pelvic floor dyssynergia requiring anorectal evaluation 1

Physical Examination Findings to Assess

• Perform digital rectal examination to identify increased/decreased sphincter tone, pelvic floor dyssynergia, rectal prolapse, anal stricture, or rectocele 1

• Observe for visible abdominal distention during or after meals to distinguish true distention from bloating sensation alone 2, 4

First-Line Treatment: Dietary Modification

Implement Short-Term Elimination Diet

• Begin with a 2-week elimination diet to diagnose food intolerances, focusing on common triggers: lactose, fructose, artificial sweeteners (sorbitol, sugar alcohols), and FODMAPs 1, 2

• Low-FODMAP diet has shown improvements in bloating and quality of life in randomized controlled trials, though it should be implemented by a trained gastroenterology dietitian with plans for reintroduction to avoid malnutrition and negative impacts on gut microbiome (decreased Bifidobacterium species) 1

• In one study, 65% of patients with functional bloating had carbohydrate malabsorption, and dietary restriction led to symptom improvement in >80% at 1 month and complete resolution in 50% at 1 year 1

Common Pitfall: Prolonged dietary restrictions without benefit lead to malnutrition and should be avoided; always plan for systematic reintroduction 4

Warning: Screen for eating disorders and avoidant/restrictive food intake disorder before implementing restrictive diets, preferably with a gastroenterology psychologist 1

Second-Line Treatment: Non-Pharmacological Interventions

For Meal-Triggered Distention (APD Pattern)

• Diaphragmatic breathing exercises reduce vagal tone and sympathetic activity, correcting the paradoxical diaphragmatic contraction that causes distention 2, 4

• Practice these exercises during and after meals when distention typically occurs 2

For Gastric Bloating Specifically

• Lie down for 30 minutes after meals to delay gastric emptying and reduce symptoms 4

• Avoid fluids until at least 30 minutes after meals to prevent further gastric distension 4

Third-Line Treatment: Pharmacological Management

For Constipation-Associated Bloating

• Secretagogues are superior to placebo for treating abdominal bloating in patients with constipation-predominant symptoms: lubiprostone, linaclotide, or plecanatide 1, 2

• A meta-analysis of 13 trials found all these medications superior to placebo with no significant differences among them 1

For Suspected SIBO or Dysbiosis

• Rifaximin (non-absorbable antibiotic) is effective for SIBO-related bloating 2, 4

• Alternative antibiotics include amoxicillin, fluoroquinolones, and metronidazole 2

For Visceral Hypersensitivity and Refractory Cases

• Central neuromodulators that activate noradrenergic and serotonergic pathways show the greatest benefit: tricyclic antidepressants (amitriptyline) or serotonin-norepinephrine reuptake inhibitors (duloxetine, venlafaxine) 1, 2

• These medications reduce perception of incoming visceral signals, re-regulate brain-gut dysregulated control mechanisms, and improve psychological comorbidities 1

• Abdominal distention improves by reducing the bloating sensation that triggers distention via the abnormal viscerosomatic reflex, working best when distention occurs during or after meals 1

• Pregabalin has also shown improvements in bloating in IBS patients 1

Fourth-Line Treatment: Specialized Interventions

For Pelvic Floor Dysfunction

• Anorectal biofeedback therapy is effective when an evacuation disorder is identified, with a 54% responder rate (50% reduction in bloating scores) in diet-refractory bloating patients 1

• Response rates are favorable and long-lasting based on RCTs, with improvements in abdominal distention, rectal hypersensitivity, and bloating 1

• Home-based biofeedback alternatives and point-of-care anorectal function testing can be used when motility specialists are unavailable 1

Brain-Gut Behavioral Therapies

• Cognitive behavioral therapy (CBT) and gut-directed hypnotherapy have robust evidence for improving bloating symptoms, particularly when psychological factors (visceral anxiety, depression, somatization) amplify sensations 2

• FDA-approved prescription-based psychological therapies are now available via smartphone apps 2

Advanced Diagnostic Testing (When First-Line Treatments Fail)

• Breath testing for hydrogen, methane, and CO2 identifies carbohydrate intolerances and SIBO 2, 4

• Anorectal physiology testing combined with balloon expulsion confirms pelvic floor dyssynergia diagnosis, especially for women with constipation-predominant symptoms not responding to standard therapies 1

• Defecography (barium or MRI) evaluates structural causes like pelvic organ prolapse or rectal intussusception when rectal pain or large rectocele/cystocele is present 1

What NOT to Use

• Probiotics are NOT recommended—insufficient data supports their use for bloating, and they may cause new onset brain fogginess, bloating, and lactic acidosis 1, 4

• Peppermint oil showed no improvement in bloating symptoms at 6-week endpoint in a recent placebo-controlled RCT, despite minimal adverse effects 1

Key Clinical Pearls

• Bloating results from multiple disturbed mechanisms along the gut-brain axis: visceral hypersensitivity, impaired central down-regulation of visceral signals, altered viscerosomatic reflexes, and psychological amplification 1, 5

• Even small increases in intraluminal gas can trigger significant distention in patients with abnormal viscerosomatic reflexes—don't attribute all distention to gas accumulation 4

• Effective communication about the biopsychosocial model and brain-gut interactions improves patient-provider relationships, health outcomes, and patient satisfaction while reducing unnecessary urgent care visits 1