What are the treatment options for irritable bowel syndrome (IBS)?

Treatment for Irritable Bowel Syndrome (IBS)

The treatment of irritable bowel syndrome requires a targeted symptom-based approach including dietary modifications, lifestyle changes, psychological interventions, and pharmacological therapies tailored to the predominant symptom (pain, diarrhea, constipation, or bloating). 1

Diagnostic Approach

• Make a positive diagnosis in patients <45 years meeting Rome criteria without alarm symptoms
• Listen to patient concerns and identify beliefs; a symptom diary may be helpful
• Provide explanation about the benign but relapsing nature of IBS and brain-gut interaction

Treatment Algorithm

Step 1: Non-Pharmacological Interventions

Dietary Modifications

• For all IBS patients:

  • Balanced diet with regular meals
  • Adequate hydration
  • Regular exercise
  • Establish regular time for defecation

• For IBS with diarrhea (IBS-D):

  • Decrease fiber intake
  • Identify and reduce intake of lactose, fructose, sorbitol, caffeine, or alcohol
  • Trial exclusion diets if appropriate

• For IBS with constipation (IBS-C):

  • Increase dietary fiber (bran)
  • If symptoms worsen, try soluble fiber (ispaghula/psyllium)

• For IBS with bloating:

  • Reduce intake of gas-producing foods (FODMAPs)
  • Trial reducing fiber/lactose/fructose as relevant 1, 2

Psychological Interventions

• Initial explanation and reassurance
• Simple relaxation therapy
• Consider referral for specialized therapies for moderate to severe symptoms:
  • Biofeedback (especially for disordered defecation)
  • Hypnotherapy
  • Cognitive behavioral therapy
  • Dynamic psychotherapy 1

Step 2: Pharmacological Treatment Based on Predominant Symptom

For Abdominal Pain

1. Antispasmodics: anticholinergic agents (dicyclomine)
2. Tricyclic antidepressants (amitriptyline/trimipramine) at low doses (10-50 mg at bedtime)
   • Especially beneficial when insomnia is prominent
   • Caution: may aggravate constipation 1

For Diarrhea (IBS-D)

1. Loperamide 4-12 mg daily (regularly or prophylactically)
2. Rifaximin 550 mg three times daily for 14 days 3
3. Eluxadoline for adults with IBS-D 4
4. Codeine 30-60 mg, 1-3 times daily (CNS side effects often limiting)
5. Cholestyramine (for select patients, but often less tolerated than loperamide) 1

For Constipation (IBS-C)

1. Increase dietary fiber (bran)
2. If symptoms worsen, try soluble fiber (ispaghula/psyllium)
3. Osmotic laxatives (polyethylene glycol)
4. Consider secretagogues for refractory symptoms 1

Special Considerations

Common Pitfalls to Avoid

• Overreliance on extensive diagnostic testing in patients meeting diagnostic criteria without alarm features
• Failure to address psychological factors contributing to symptoms
• Using opioid analgesics for chronic abdominal pain (can worsen GI dysmotility)
• Insoluble fiber supplementation may worsen symptoms in some patients 1

Treatment Monitoring

• Review efficacy after 3 months
• Discontinue medications if no response
• Rotate antibiotics if using for suspected bacterial overgrowth
• Monitor for medication side effects, especially with tricyclic antidepressants 1

When to Refer

• Diagnostic uncertainty
• Severe or refractory symptoms
• Need for specialized dietary intervention (referral to dietitian)
• Significant psychological comorbidity (referral to psychology)
• Patient request for specialist opinion 1

The treatment of IBS should focus on improving quality of life by targeting the most bothersome symptoms. While pharmacological options have limited efficacy, a structured approach addressing diet, lifestyle, psychological factors, and targeted symptom management can provide significant relief for many patients.