What are the treatment options for Irritable Bowel Syndrome (IBS)?

Treatment Options for Irritable Bowel Syndrome (IBS)

Treatment of IBS should follow a step-wise approach, starting with dietary modifications and lifestyle changes, followed by targeted pharmacological interventions based on predominant symptoms, and psychological therapies for refractory cases. 1

Dietary and Lifestyle Modifications (First-Line)

• Soluble fiber supplementation: Start with ispaghula (psyllium) at 3-4g/day and gradually increase for constipation symptoms 1
• Low FODMAP diet: Recommended for moderate to severe symptoms, implemented by a trained dietitian 1
• Symptom diary: Use to identify triggers and monitor treatment response 1
• Avoid gas-producing foods: Reduce intake of foods high in fiber, lactose, or fructose 1
• Mediterranean diet: Consider for patients with psychological-predominant symptoms 1

Pharmacological Treatment by Predominant Symptom

For Abdominal Pain

1. Antispasmodics (e.g., dicyclomine): First-line treatment for abdominal pain 1
2. Peppermint oil: Effective for pain relief 1
3. Tricyclic antidepressants (e.g., amitriptyline 10-50mg at bedtime): For pain with sleep disturbance 1

For IBS with Diarrhea (IBS-D)

1. Loperamide: Initial dose of 4 mg followed by 2 mg every 4 hours or after every unformed stool (max 16 mg/day) 1
2. Codeine: 15-30 mg, 1-3 times daily as a second-line agent (caution: may cause sedation) 1
3. Alosetron: For severe IBS-D that hasn't responded to other treatments 1
4. Rifaximin: 550mg twice daily for 1-2 weeks if small intestinal bacterial overgrowth (SIBO) is suspected 1

For IBS with Constipation (IBS-C)

1. Linaclotide: FDA-approved secretagogue for IBS-C with proven efficacy in clinical trials 2
   • Clinical trials showed 12-13% response rate (vs. 3-5% for placebo) for combined symptom improvement 2
   • 34-39% of patients experienced ≥30% reduction in abdominal pain (vs. 20-27% for placebo) 2
2. Polyethylene glycol: Add if inadequate response to fiber 1

Psychological Therapies (For Refractory Symptoms)

• Cognitive Behavioral Therapy (CBT): Effective in 4-12 sessions, focusing on pain catastrophizing and visceral anxiety 1
• Gut-directed hypnotherapy: Focuses on somatic awareness and down-regulation of pain sensations 1
• Mindfulness-based stress reduction: Improves specific symptoms like constipation, diarrhea, bloating, and gastrointestinal-specific anxiety 1

Treatment Algorithm

1. Initial approach: Dietary modifications and lifestyle changes
2. Add: Soluble fiber and/or peppermint oil
3. If inadequate response: Add polyethylene glycol for constipation or loperamide for diarrhea
4. If still inadequate response: Add a secretagogue (linaclotide preferred for IBS-C based on efficacy) 1, 2
5. For persistent symptoms: Add an antispasmodic or gut-brain neuromodulator (tricyclic antidepressants, SNRIs, or SSRIs)
6. For severe or refractory symptoms: Consider psychological therapies and multidisciplinary approach 1

Important Considerations

• Set realistic expectations: Complete symptom resolution is often not achievable; efficacy of all IBS treatments is modest 1
• Regular monitoring: Review efficacy after 3 months and discontinue ineffective treatments 1
• Specialist referral: Consider referral to a gastroenterologist when diagnostic uncertainty exists, symptoms are severe or refractory to first-line treatments 1
• Brain-gut axis: Anxiety, catastrophizing, and hypervigilance contribute to symptom severity and should be addressed 1
• Coordination of care: For patients with mental health comorbidities, coordination between gastroenterology and mental health providers is essential 1