What medications are used to treat gas and bloating?

Medications for Gas and Bloating

Start with antispasmodics for first-line symptom relief, followed by secretagogues if constipation is present, or central neuromodulators (tricyclic antidepressants) for refractory cases with visceral hypersensitivity.

First-Line Pharmacological Options

Antispasmodics

• Certain antispasmodics are effective for global symptoms and abdominal pain in IBS, including bloating 1
• Common side effects include dry mouth, visual disturbance, and dizziness 1
• These should be considered as initial pharmacological therapy when dietary modifications fail 1

Simethicone-Based Combinations

• Simethicone is an antifoaming agent that reduces bloating and abdominal discomfort 2
• Combination products containing simethicone with chitin-glucan showed 67% responder rate for abdominal pain and 60% for bloating at 4 weeks 3
• Loperamide-simethicone combination provides faster relief of gas-related abdominal discomfort than either component alone in acute diarrhea with bloating 4
• These combinations are well-tolerated with good safety profiles 5, 2, 3

Second-Line Medications Based on Bowel Pattern

For Bloating with Constipation (IBS-C)

• Secretagogues are superior to placebo for treating abdominal bloating when constipation is present 1, 6
• Linaclotide 290 μg once daily is the most efficacious secretagogue available for IBS-C, showing improvement in bloating in 4 trials with 3,061 patients 1
• Lubiprostone 8 μg twice daily is less likely to cause diarrhea than other secretagogues but nausea is a frequent side effect 1
• Plecanatide and tenapanor are alternative secretagogues with similar efficacy 1
• All secretagogues work by activating ion channels, resulting in water efflux into the intestinal lumen 1

For Bloating with Diarrhea (IBS-D)

• Rifaximin 550 mg three times daily for 14 days is efficacious for IBS-D, with 41% achieving adequate relief of IBS symptoms including bloating 7
• Rifaximin is a non-absorbable antibiotic that is FDA-approved for IBS-D 7
• Alternative antibiotics include amoxicillin, fluoroquinolones, and metronidazole, though these require careful patient selection 1, 6
• Loperamide may be effective for diarrhea but can worsen bloating, nausea, and constipation; careful dose titration is required 1

Central Neuromodulators for Refractory Bloating

Tricyclic Antidepressants (TCAs)

• TCAs are effective second-line drugs for global symptoms and abdominal pain in IBS, including bloating 1
• Start amitriptyline at 10 mg once daily and titrate slowly to maximum of 30-50 mg once daily 1
• TCAs reduce visceral sensations by activating noradrenergic and serotonergic pathways 1
• These work best when distention occurs during or after meals 1
• Careful explanation of rationale and counseling about side effects is required 1

SNRIs and Other Neuromodulators

• Serotonin-norepinephrine reuptake inhibitors (duloxetine, venlafaxine) show benefit for bloating and global symptoms 1, 6
• Pregabalin has shown improvements in bloating in patients with IBS 1
• These medications re-regulate brain-gut dysregulated control mechanisms and improve psychological comorbidities 1

Diagnostic-Directed Therapy

For Small Intestinal Bacterial Overgrowth (SIBO)

• Rifaximin is the most studied antibiotic for SIBO-related bloating 1, 6
• Hydrogen-based breath testing with glucose or lactulose can confirm SIBO diagnosis 1, 6
• High-risk patients include those with chronic watery diarrhea, malnutrition, weight loss, and systemic diseases causing small bowel dysmotility 1, 6

For Carbohydrate Intolerance

• Begin with a 2-week dietary elimination trial before considering medications 1, 6
• Fructose intolerance affects 60% and lactose intolerance affects 51% of patients with digestive symptoms 1, 6
• Breath testing should be reserved for patients refractory to dietary restrictions 1

Important Caveats

What NOT to Use

• Probiotics should not be used to treat abdominal bloating and distention 8
• In fact, probiotics may worsen symptoms in some patients with SIBO and can contribute to D-lactic acidosis and brain fogginess 9
• Proton pump inhibitors have limited effectiveness for bloating unless directly associated with GERD symptoms 10, 8
• Opioid analgesics should not be used for chronic abdominal pain as they delay gastric emptying and worsen gas symptoms 6

Titration and Monitoring

• Loperamide requires careful dose titration to avoid worsening bloating and constipation 1
• Secretagogues commonly cause diarrhea as a side effect; this limits tolerability 1
• Central neuromodulators should be started at low doses and titrated slowly 1

Treatment Duration

• Probiotics, if used despite limited evidence, should be discontinued after 12 weeks if no improvement occurs 1
• Rifaximin for IBS-D is given as 14-day courses, with repeat courses for symptom recurrence 7
• After antibiotic treatment for SIBO, symptoms improved in 77% of patients when probiotics were also discontinued 9