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

Treatment Options for Irritable Bowel Syndrome (IBS)

An integrated care approach that addresses gastrointestinal symptoms through a combination of dietary modifications, brain-gut behavioral therapies, and targeted pharmacological interventions is the gold standard treatment for irritable bowel syndrome. 1

Diagnosis Considerations

IBS is defined as recurrent abdominal pain at least 1 day/week in the last 3 months associated with defecation changes, according to Rome IV criteria. Before initiating treatment, confirm diagnosis with:

• Full blood count
• C-reactive protein or ESR
• Coeliac serology
• Fecal calprotectin (for patients under 45 years with diarrhea) 1

Step-wise Treatment Approach

Step 1: Dietary and Lifestyle Modifications

• Low-FODMAP diet: Recommended for patients with moderate to severe gastrointestinal symptoms, implemented under supervision of a trained dietitian 1
• Mediterranean diet: Beneficial for patients with psychological-predominant symptoms 1
• Fiber supplementation:
  • Soluble fiber (ispaghula): Start at 3-4g/day and gradually increase for IBS-D 1
  • Avoid insoluble fiber (wheat bran) as it may worsen symptoms 1
• Regular physical activity: Beneficial for reducing IBS symptoms 1
• Stress reduction techniques and improved sleep hygiene 1

Step 2: First-line Pharmacological Interventions

• For IBS-D (diarrhea predominant):

  • Loperamide 4-12 mg daily 1
  • Cholestyramine for patients with evidence of bile acid malabsorption 1
  • Rifaximin (Xifaxan) 550 mg three times daily for 14 days - FDA-approved for IBS-D 1, 2

• For IBS-C (constipation predominant):

  • Add polyethylene glycol 1
  • If inadequate response, add a secretagogue (linaclotide preferred based on efficacy) 1

• For pain management:

  • Antispasmodics for abdominal pain and bloating 1
  • Peppermint oil 1

Step 3: Second-line Pharmacological Interventions

• Tricyclic antidepressants (e.g., amitriptyline): Start at 10 mg at bedtime, titrate slowly by 10 mg per week as needed, target dose 25-50 mg at bedtime 1
• Selective serotonin reuptake inhibitors (SSRIs): Recommended for patients with comorbid anxiety disorders 1

Step 4: Psychological Therapies

• Brain-gut behavioral therapies (BGBTs):
  • Cognitive-behavioral therapy
  • Gut-directed hypnotherapy
  • Mindfulness-based stress reduction 1
• Especially beneficial for patients who:
  • Connect symptom flares with stress
  • Have anxiety or depression
  • Have relatively recent symptom onset 1

IBS Subtype-Specific Considerations

IBS-D (Diarrhea Predominant)

• Rifaximin has shown efficacy in clinical trials, with 44% of patients responding to initial treatment 2
• For patients who experience recurrence after initial response, repeat treatment courses may be beneficial 2
• Loperamide and cholestyramine are effective options 1, 3

IBS-C (Constipation Predominant)

• Polyethylene glycol and secretagogues are recommended 1
• High-fiber diet may be beneficial 1

IBS-M (Mixed Pattern)

• Treatment should target the most bothersome symptoms 1
• Combination approaches may be necessary 4

When to Refer

• Consider referral to a dietitian when:

  • Patient reports considerable intake of trigger foods
  • Has dietary deficits
  • Shows food-related fear 1

• Consider referral to a psychologist when:

  • Symptoms are moderate to severe
  • Patient accepts the gut-brain connection
  • Has time for learning coping strategies 1

• Consider referral to gastroenterology when:

  • Diagnostic uncertainty exists
  • Symptoms are severe or refractory to first-line treatments
  • Patient requests a specialist opinion 1

Treatment Monitoring

• Review efficacy after 3 months of treatment
• Discontinue if no response 1
• Use symptom diaries to identify triggers and monitor treatment response 1
• Avoid unnecessary colonoscopies unless alarm symptoms are present 1

Common Pitfalls and Caveats

• Avoid insoluble fiber in patients with IBS-D as it may worsen symptoms 1
• Don't overlook psychological factors - stress and anxiety can significantly exacerbate IBS symptoms 1
• Beware of overdiagnosis - ensure appropriate diagnostic testing to exclude inflammatory bowel disease, celiac disease, and microscopic colitis 1
• Monitor for medication side effects - tricyclic antidepressants can cause constipation, dry mouth, and drowsiness 1
• Rifaximin should not be used in patients with diarrhea complicated by fever or blood in the stool 2

Individual dietary guidance has been shown to reduce symptoms and improve quality of life in IBS patients, making it a cost-effective management option 5.