What are the recommended over-the-counter (OTC) medications, including doses, for a patient experiencing bloatedness?

Over-the-Counter Medications for Bloatedness

For symptomatic relief of bloating, simethicone 80-125 mg after meals and at bedtime (up to 500 mg daily) is the most commonly used OTC option, though evidence for its efficacy is limited. For patients with bloating associated with constipation, polyethylene glycol (PEG) 17 grams daily is the most evidence-based OTC choice. 1, 2

First-Line OTC Approach Based on Clinical Context

For Bloating Alone (Without Constipation)

• Simethicone: 80-125 mg after meals and at bedtime, maximum 500 mg daily 3
  • Acts as an anti-foaming agent to reduce gas bubbles
  • Well-tolerated with excellent safety profile 3
  • Important caveat: Evidence for efficacy is modest; one comparative study showed it was inferior to combination products for functional bloating 3

For Bloating with Constipation

• Polyethylene glycol (PEG): 17 grams (one capful) dissolved in 8 oz of liquid once daily 1, 2

  • Grade A recommendation with good evidence for chronic constipation 2
  • Osmotic laxative that softens stool and may reduce bloating secondary to constipation 1
  • Cost-effective at <$50 per month 1
  • Can titrate dose based on symptom response 1

• Magnesium oxide: 400-500 mg daily, though studies have used 1,000-1,500 mg daily 1

  • Osmotic laxative mechanism 1
  • Critical warning: Use with caution in renal insufficiency and pregnancy 1
  • May worsen bloating at higher doses due to gas production 1

Short-Term or Rescue Therapy

• Senna: 8.6-17.2 mg daily, maximum 4 tablets twice daily (approximately 68.8 mg/day) 1, 4

  • Stimulant laxative with Grade A evidence for constipation 2
  • Important limitation: Recommended for short-term use only; long-term safety unknown 1, 4
  • Side effects include cramping and abdominal discomfort 1

• Bisacodyl: 5 mg daily, maximum 10 mg daily 1

  • Stimulant laxative for short-term or rescue use 1
  • Rare but serious concern: Associated with rare cases of ischemic colitis 1

Dietary Fiber Considerations

• Soluble fiber (psyllium/ispaghula): Start low at 3-4 grams daily, gradually increase 5
  • Grade B evidence for constipation 2
  • Critical pitfall: Can worsen bloating if started at high doses or if patient has pre-existing bloating 1, 5
  • More effective than insoluble fiber (wheat bran) 6

What NOT to Use

• Avoid hyoscyamine/antispasmodics: May worsen constipation due to anticholinergic effects 7
• Probiotics not recommended: The AGA specifically states probiotics are not recommended for bloating or distention; may cause brain fog and lactic acidosis in some patients 5

When OTC Options Are Insufficient

If bloating persists despite OTC therapy, prescription options with strong evidence include:

• Linaclotide 290 μg daily: Most efficacious for bloating in IBS-C (NNT=7), though diarrhea is common side effect 1, 8
• Lubiprostone 8 μg twice daily: Effective for bloating with lower diarrhea risk but nausea is common 1
• Rifaximin: May reduce bloating by altering gut microbiota, particularly if small intestinal bacterial overgrowth suspected 9, 10, 3

Common Pitfalls to Avoid

• Starting fiber supplements at high doses, which paradoxically worsens bloating 5
• Using anticholinergic agents in patients with constipation-associated bloating 7
• Relying on probiotics without evidence of benefit 5
• Ignoring underlying causes: lactose intolerance, celiac disease, pelvic floor dysfunction 5
• Prolonged use of stimulant laxatives without medical supervision 1, 4

Practical Algorithm

1. If bloating alone: Trial simethicone 80-125 mg after meals and bedtime
2. If bloating + constipation: Start PEG 17 grams daily
3. If inadequate response: Add senna 8.6-17.2 mg for short-term rescue
4. If persistent symptoms >4 weeks: Consider prescription secretagogues or evaluation for underlying disorders 1, 5