What is the treatment for Irritable Bowel Syndrome (IBS)?

Treatment of Irritable Bowel Syndrome (IBS)

The most effective treatment for IBS requires a comprehensive approach including dietary modifications, lifestyle changes, psychological interventions, and targeted pharmacological therapy based on predominant symptoms. 1, 2

Diagnostic Approach

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

First-Line Interventions

Dietary Modifications

• Low FODMAP diet is the first-line dietary approach for moderate to severe symptoms 2, 3
  • Should be implemented under supervision of a trained dietitian
  • Shown to be more effective than standard diet for symptom improvement 3
• Assess and modify fiber intake based on predominant symptoms:
  • Increase soluble fiber for constipation (ispaghula/psyllium)
  • Decrease fiber for diarrhea
• Identify and eliminate food triggers:
  • Excessive lactose, fructose, sorbitol, caffeine, or alcohol in diarrhea-predominant IBS
  • Consider personalized dietary approach based on food sensitivity testing 4

Lifestyle Modifications

• Regular exercise
• Establish regular time for defecation
• Stress management techniques
• Adequate sleep hygiene

Pharmacological Treatment Based on Predominant Symptoms

For Abdominal Pain

• Antispasmodics (anticholinergic agents like dicyclomine) 1
• Peppermint oil (high efficacy for pain relief) 5
• Tricyclic antidepressants (amitriptyline 10-50mg at bedtime) 1, 2
  • Start low (10mg) and titrate by 10mg weekly to target 25-50mg
  • Particularly effective for pain with sleep disturbances
  • Works through neuromodulatory and analgesic properties
  • More effective in patients ≥50 years of age
  • Avoid in patients with severe constipation, cardiac conduction abnormalities, or narrow-angle glaucoma

For Diarrhea-Predominant IBS

• Loperamide 4-12mg daily (regularly or prophylactically) 1
• Cholestyramine (for a small subset of patients, less tolerated than loperamide) 1
• Codeine 30-60mg 1-3 times daily (CNS side effects often limit use) 1

For Constipation-Predominant IBS

• Linaclotide (290mcg once daily) 6
  • FDA-approved for IBS-C in adults
  • Significantly improves abdominal pain and increases complete spontaneous bowel movements
• Polyethylene glycol for inadequate response to fiber 2
• Secretagogues for refractory symptoms 2

For Bloating

• Reduce intake of gas-producing foods (fiber/lactose/fructose) 1
• Consider probiotics (moderate efficacy) 5, 7

Psychological Interventions

• Initial explanation and reassurance
• Simple relaxation therapy
• For moderate to severe symptoms, consider:
  • Cognitive behavioral therapy
  • Gut-directed hypnotherapy (exclude those with overt psychiatric disease)
  • Biofeedback (especially for disordered defecation)
  • Mindfulness-based stress reduction 2

Treatment Algorithm

1. Start with dietary modifications and lifestyle changes
2. Add soluble fiber and/or peppermint oil
3. If inadequate response, add targeted pharmacological therapy based on predominant symptoms:
   • For pain: antispasmodics or low-dose tricyclic antidepressants
   • For diarrhea: loperamide
   • For constipation: polyethylene glycol, then linaclotide if needed
4. For persistent symptoms, add gut-brain neuromodulators
5. For severe or refractory symptoms, implement psychological therapies 2, 8

Follow-up and Referral

• Review efficacy after 3 months and discontinue ineffective treatments
• Consider referral to gastroenterology for:
  • Diagnostic uncertainty
  • Severe or refractory symptoms
  • Patient request for specialist opinion 2
• Refer to dietitian when:
  • Patient reports significant trigger foods
  • Has dietary deficits
  • Shows food-related fear 2
• Refer to psychologist when:
  • Symptoms are moderate to severe
  • Patient accepts the gut-brain connection 2

Common Pitfalls to Avoid

• Overuse of investigations in patients meeting diagnostic criteria without alarm features
• Prescribing opioid analgesics for chronic abdominal pain (worsens GI dysmotility)
• Long-term metronidazole use (can cause peripheral neuropathy)
• High-dose loperamide (risk of QT prolongation)
• Insoluble fiber supplementation (may worsen symptoms) 2
• Failing to address psychological factors contributing to symptom exacerbation