What is the treatment for irritable bowel syndrome (IBS)?

Treatment of Irritable Bowel Syndrome (IBS)

The treatment of irritable bowel syndrome should begin with lifestyle modifications and dietary changes, followed by targeted pharmacological therapies based on predominant symptoms, and psychological interventions for refractory cases. 1

Initial Management Approach

• Make a positive diagnosis in patients <45 years meeting three or more IBS criteria without sinister symptoms, avoiding unnecessary extensive testing 2
• Listen to the patient's concerns, identify their beliefs, and consider using a symptom diary to track patterns 2
• Provide clear explanation about IBS as a brain-gut interaction disorder with a benign but relapsing/remitting course 2
• Discuss how stress may aggravate symptoms or worsen worry about the condition 2

Lifestyle and Dietary Modifications

• Recommend regular physical exercise to all patients with IBS 1
• Advise a balanced diet with appropriate fiber intake based on symptom type 2
• For constipation-predominant IBS: increase dietary fiber (preferably soluble fiber like ispaghula/psyllium) starting with low doses (3-4g/day) and gradually increasing 1
• For diarrhea-predominant IBS: decrease fiber intake and identify potential triggers 2
• Identify and reduce intake of potential triggers such as excessive lactose, fructose, sorbitol, caffeine, or alcohol, especially in patients with diarrhea 2
• Consider probiotics for a 12-week trial period for global symptom improvement 1
• Avoid recommending diets based on IgG antibody testing or gluten-free diets unless celiac disease is confirmed 1

Pharmacological Treatment by Predominant Symptom

For Abdominal Pain

• Antispasmodics (anticholinergic agents like dicyclomine) can help reduce pain but may cause side effects like dry mouth and visual disturbances 2
• Peppermint oil may be useful as an antispasmodic alternative with fewer side effects 1
• For persistent pain, consider tricyclic antidepressants (amitriptyline/trimipramine) starting at low doses (10mg daily) and gradually increasing to 30-50mg if needed 1

For Diarrhea-Predominant IBS (IBS-D)

• Loperamide 4-12mg daily (either regularly or prophylactically before going out) is effective for controlling diarrhea 2
• Rifaximin (550mg three times daily for 14 days) is FDA-approved for IBS-D, with possible retreatment for symptom recurrence up to two times 3
• Eluxadoline is indicated for adults with IBS-D 4
• Cholestyramine may benefit some patients but is often less well tolerated than loperamide 2

For Constipation-Predominant IBS (IBS-C)

• Increase dietary fiber or use ispaghula/psyllium supplements 2
• Avoid insoluble fiber (like wheat bran) as it may worsen symptoms 1
• Consider osmotic laxatives if fiber supplementation is insufficient 5, 6

For Bloating

• Reduce intake of fermentable carbohydrates (fiber/lactose/fructose) as relevant 2
• Consider a low FODMAP diet (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) following its three phases: restriction, reintroduction, and personalization 7

Psychological Interventions for Refractory Cases

• For patients with persistent symptoms despite first-line treatments, consider psychological therapies 1
• Initial approach should include explanation, reassurance, and simple relaxation techniques 2
• More specialized therapies include:
  • Cognitive behavioral therapy specifically designed for IBS 1, 7
  • Gut-directed hypnotherapy (excluding those with overt psychiatric disease) 2, 1
  • Biofeedback (especially for disordered defecation) 2
• Refer to psychiatric services for serious psychiatric comorbidities 2

Treatment Monitoring and Duration

• Review treatment efficacy after 3 months and discontinue ineffective therapies 1
• Continue tricyclic antidepressants for at least 6 months if symptomatically beneficial 1
• For patients using rifaximin, monitor for symptom recurrence and consider retreatment if needed 3

Common Pitfalls to Avoid

• Avoid extensive investigations once IBS diagnosis is established 1
• Do not recommend elimination diets based on IgG antibody testing 1
• Recognize that true food allergies are rare, but food intolerances are common 2
• Be aware of potential development of Clostridium difficile-associated diarrhea with antibiotic use, including rifaximin 3
• Consider the psychological aspects of IBS and address comorbid mental health conditions 1, 8