What medications are used to treat bloating?

Medications for Bloating

Central neuromodulators, specifically low-dose tricyclic antidepressants (TCAs) starting at 10 mg amitriptyline once daily and titrating to 30-50 mg, are the most effective first-line pharmacological treatment for bloating by reducing visceral hypersensitivity, with 61% of patients reporting symptom improvement. 1, 2

Treatment Algorithm Based on Clinical Presentation

Bloating with Constipation (IBS-C)

• Start with secretagogues as first-line therapy: linaclotide (72-290 μg daily), lubiprostone (24 μg twice daily), or plecanatide, which address both constipation and bloating with a number needed to treat (NNT) of 8 for moderate-severe bloating improvement 3, 2, 4
• Linaclotide 290 μg once daily demonstrated superiority over placebo for abdominal bloating in 4 trials containing 3,061 patients 3
• Lubiprostone activates chloride channels, increasing intestinal fluid secretion and softening stools; take with food and water to minimize nausea 3, 5
• Alternative option: prucalopride (5-HT4 agonist) provides additional benefit for abdominal pain along with improving constipation 4

Functional Bloating (Without Constipation or Diarrhea)

• Start with low-dose TCAs: amitriptyline 10 mg once daily at bedtime, titrate by 10 mg weekly or biweekly to target dose of 30-50 mg based on response 1, 2
• TCAs work by reducing visceral hypersensitivity and improving disrupted brain-gut control mechanisms that cause bloating perception despite normal gas volumes 1, 2
• Alternative neuromodulators: SNRIs (duloxetine or venlafaxine) activate both noradrenergic and serotonergic pathways for bloating with pain 1
• Allow 6-8 weeks for full therapeutic response before declaring treatment failure 1

Bloating with Diarrhea (IBS-D)

• Consider rifaximin: 550 mg three times daily for 14 days, a non-absorbable antibiotic that improves global IBS symptoms and bloating, though its effect on abdominal pain is limited 3
• Rifaximin can be repeated if symptoms relapse, with no significant safety concerns in retreatment trials 3
• 5-HT3 receptor antagonists: ondansetron titrated from 4 mg once daily to maximum 8 mg three times daily (constipation is the most common side effect, so monitor carefully) 3

Adjunctive Therapies

Dietary Modifications

• Low FODMAP diet reduces bacterial fermentation and gas production, but avoid in malnourished patients 2
• Identify and restrict carbohydrate intolerances (lactose, fructose, sucrose) through 2-week dietary elimination trial as the simplest and most economical diagnostic approach 3

Probiotics and Other Options

• Peppermint oil may provide benefit with minimal side effects, though evidence remains limited 2
• Probiotics show promise for bloating management, particularly in patients with small intestinal bacterial overgrowth (SIBO) 6, 7
• Simethicone has limited efficacy as monotherapy but may provide modest symptom relief 8, 9

Behavioral Interventions

• Biofeedback therapy for patients with objective abdominal distention due to abdominophrenic dyssynergia (abnormal diaphragm contraction and abdominal wall relaxation) 2, 4
• Cognitive behavioral therapy (CBT) or hypnotherapy improves quality of life in refractory cases 2

Critical Medications to AVOID

Domperidone and Metoclopramide

• Do NOT use domperidone for functional bloating: significant cardiac safety risks including QT prolongation, arrhythmias, and sudden cardiac death, particularly at doses >30 mg/day and in patients >60 years old 2
• The American Gastroenterological Association does not recommend domperidone for bloating due to lack of efficacy evidence 2
• The British Society of Gastroenterology recommends against long-term use of domperidone and metoclopramide for gastrointestinal motility disorders including bloating 2

Hyoscyamine

• Avoid hyoscyamine in bloating with constipation: anticholinergic effects may worsen constipation, and limited evidence supports its efficacy for bloating 4

Opioids

• Never use opioids for chronic GI pain or bloating: they are ineffective and increase harm risk 1

Implementation Pearls

Setting Expectations

• Counsel patients that complete symptom resolution is often not achievable; the goal is meaningful symptom reduction 1
• Explain mechanism of action: neuromodulators work on brain-gut axis, not as traditional antidepressants at these doses 1
• Validate symptoms and discuss potential side effects before starting treatment 1

Monitoring and Duration

• Continue successful treatment for 6-12 months after initial response to prevent relapse 1
• Assess periodically the need for continuous therapy with secretagogues 5
• For TCAs, start low (10 mg) to minimize side effects and improve adherence 1

When to Escalate

• Move to neuromodulators when symptoms persist despite first-line therapies (dietary modifications, fiber, antispasmodics, peppermint oil) 1
• Consider combination therapy: secretagogue for constipation plus TCA for visceral hypersensitivity in refractory cases 2, 4