How should I manage a patient presenting with abdominal bloating in the absence of red‑flag symptoms such as fever, weight loss, persistent vomiting, gastrointestinal bleeding, or severe pain?

Management of Abdominal Bloating Without Red-Flag Symptoms

Begin with Rome IV diagnostic criteria to classify the bloating, then implement a stepwise treatment approach starting with dietary modification under dietitian supervision, followed by central neuromodulators if symptoms persist, while explicitly avoiding probiotics. 1

Initial Diagnostic Framework

Clinical History Essentials

• Assess meal-related patterns: Document whether bloating worsens after eating and identify specific food triggers 2
• Evaluate bowel habits systematically: Use Bristol Stool Scale to characterize stool consistency, assess for straining with soft stool (suggesting pelvic floor dyssynergia), and inquire about incomplete evacuation sensation 2
• Screen for carbohydrate intolerances: Specifically ask about lactose, fructose, and gluten consumption and their correlation with symptoms 1, 2
• Review medications comprehensively: Many commonly used drugs cause constipation and bloating 2

When to Order Testing

Imaging and endoscopy should only be ordered if alarm features, recent symptom worsening, or abnormal physical examination are present 1. In the absence of red flags as specified in your question, extensive testing is not indicated.

However, consider these targeted investigations:

• Celiac disease screening: Obtain tissue transglutaminase IgA with total IgA levels, particularly if any suggestion of malabsorption exists 1, 3
• Breath testing: May be used to evaluate carbohydrate enzyme deficiencies through dietary restriction and/or breath testing 1
• Small intestinal bacterial overgrowth (SIBO): Only in a small subset of at-risk patients, use small bowel aspiration or glucose/lactulose-based hydrogen breath testing 1
• Gastric emptying studies: Should NOT be ordered routinely for bloating, but may be considered only if nausea and vomiting are prominent 1
• Anorectal physiology testing: Suggested when bloating relates to constipation or difficult evacuation to rule out pelvic floor disorder 1

Treatment Algorithm

First-Line: Dietary Intervention

Dietary modifications with low-FODMAP diet should be the initial approach, preferably monitored by a gastroenterology dietitian 1. This is critical because:

• The low-FODMAP diet targets fermentable oligosaccharides, disaccharides, monosaccharides, and polyols that contribute to gas production and bloating 1
• A gastroenterology dietitian should be part of the multidisciplinary approach to ensure proper implementation and nutritional adequacy 1
• Standard dietary advice should be provided for mild symptoms, escalating to low-FODMAP for moderate to severe symptoms 1

Second-Line: Pharmacological Management

Central Neuromodulators (Antidepressants)

Central neuromodulators are the primary pharmacological option, working by reducing visceral hypersensitivity, raising sensation threshold, and improving psychological comorbidities 1:

• Low-dose tricyclic antidepressants (TCAs): Should be first choice, initiated at low doses and titrated according to symptomatic response 1
• SSRIs: Offer an alternative if symptoms do not respond to TCAs 1
• TCAs have the added benefit of potentially helping with diarrhea-predominant symptoms by prolonging gut transit time 1

Constipation-Targeted Therapy

If constipation symptoms coexist, medications used to treat constipation should be considered for treating bloating 1. Options include:

• Lubiprostone 4
• Linaclotide 4
• Prokinetic agents 4

What NOT to Use

Probiotics should NOT be used to treat abdominal bloating and distention 1. This is an explicit recommendation from the 2023 AGA guidelines despite their widespread use.

Third-Line: Behavioral and Psychological Interventions

Brain-gut behavioral therapies are effective for bloating and should be considered, particularly for refractory cases 1:

• Cognitive behavioral therapy (CBT): Useful for moderate to severe symptoms 1
• Hypnotherapy: Can be used for moderate to severe gastrointestinal symptoms 1
• Diaphragmatic breathing: Specifically helpful for abdominophrenic dyssynergia 1
• Biofeedback therapy: May be effective when a pelvic floor disorder is identified 1

Special Considerations

Abdominophrenic Dyssynergia

If abnormal viscero-somatic reflexes are suspected (where patients paradoxically protrude their abdomen in response to bloating sensation):

• Treat with diaphragmatic breathing and central neuromodulators 1
• This represents a specific subtype requiring targeted intervention

Pelvic Floor Dysfunction

When bloating relates to constipation or difficult evacuation:

• Obtain anorectal physiology testing to identify pelvic floor disorders 1
• Biofeedback therapy is effective when pelvic floor disorder is confirmed 1

Common Pitfalls to Avoid

• Do not routinely order gastric emptying or whole gut motility studies unless additional treatment-refractory symptoms warrant testing for neuromyopathic disorders 1
• Do not prescribe probiotics despite patient requests or widespread marketing—evidence does not support their use 1
• Do not skip dietitian involvement when implementing dietary modifications, as improper FODMAP restriction can lead to nutritional deficiencies 1
• Do not overlook psychological comorbidities, as these significantly impact treatment response and may require combined medical and psychological approaches 1

Simethicone Consideration

While simethicone is FDA-approved for relief of pressure and bloating commonly referred to as gas 5, it is not prominently featured in the most recent high-quality guidelines, suggesting limited efficacy for chronic functional bloating compared to the approaches outlined above.