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

Management of Irritable Bowel Syndrome (IBS)

Begin with a positive diagnosis based on symptoms in patients under 45 without alarm features, then implement a stepwise approach starting with lifestyle modifications and dietary interventions, followed by symptom-targeted pharmacotherapy, and reserve psychological therapies for refractory cases. 1

Initial Management and Patient Education

• Provide clear explanation that IBS is a disorder of gut-brain interaction with a benign but relapsing/remitting course to establish realistic expectations and reduce patient anxiety 2, 1
• Listen to patient concerns, identify their beliefs about the condition, and address fears directly rather than ordering extensive testing once diagnosis is established 2, 1
• Consider using a symptom diary to track triggers and patterns, which helps guide treatment decisions 1
• Emphasize that stress may aggravate symptoms or impair coping abilities, introducing the concept of brain-gut interaction 2

Lifestyle Modifications (First-Line for All Patients)

• Recommend regular physical activity to all patients with IBS, as exercise provides significant benefits for symptom management 1
• Advise balanced diet with adequate fiber intake, regular time for defecation, and proper sleep hygiene 2
• Identify and reduce excessive intake of lactose, fructose, sorbitol, caffeine, or alcohol, particularly in diarrhea-predominant patients 2, 1

Dietary Interventions

• Start with soluble fiber supplementation (ispaghula/psyllium) at low doses (3-4 g/day) and gradually increase for constipation-predominant IBS (IBS-C), as this is effective for global symptoms and pain 1
• Avoid insoluble fiber (wheat bran) as it may worsen symptoms, particularly bloating 1
• For persistent symptoms despite initial measures, refer to a trained dietitian for a supervised trial of low FODMAP diet delivered in three phases: restriction, reintroduction, and personalization 2, 1
• Do not recommend gluten-free diet unless celiac disease is confirmed, and avoid IgG-based food elimination diets 1
• For bloating specifically, trial reducing fiber, lactose, and fructose intake as relevant 2, 1

Pharmacological Treatment by Predominant Symptom

For Abdominal Pain and Cramping

• Use antispasmodics (anticholinergic agents like dicyclomine) as first-line therapy for abdominal pain, particularly when symptoms are meal-related 2, 1
• Peppermint oil may be useful as an alternative antispasmodic, though evidence is more limited 1
• If pain persists, initiate low-dose tricyclic antidepressants (TCAs) such as amitriptyline starting at 10 mg once daily, titrating slowly to maximum 30-50 mg once daily 1
• TCAs are especially effective when insomnia is prominent, but may aggravate constipation 2, 1

For Diarrhea-Predominant IBS (IBS-D)

• Loperamide 4-12 mg daily (either regularly or prophylactically before going out) is first-line therapy to reduce stool frequency, urgency, and fecal soiling 2, 1
• Codeine 30-60 mg, 1-3 times daily can be tried but central nervous system effects often limit tolerability 2, 1
• Rifaximin (non-absorbable antibiotic) is effective as second-line therapy for IBS-D, though its effect on abdominal pain is limited 3
• Cholestyramine may benefit a small subset with bile salt malabsorption (particularly post-cholecystectomy) but is often less well tolerated than loperamide 2, 1

For Constipation-Predominant IBS (IBS-C)

• Increase dietary fiber or use soluble fiber supplements (ispaghula/psyllium) as first-line approach 1
• For patients who fail to respond to fiber supplementation, linaclotide (guanylate cyclase-C agonist) 290 mcg once daily is effective second-line therapy, though diarrhea is a common side effect 4
• In clinical trials, 12-13% of patients achieved combined response (≥30% abdominal pain reduction plus ≥3 complete spontaneous bowel movements with ≥1 increase from baseline) for at least 9 out of 12 weeks, compared to 3-5% with placebo 4

For Mixed IBS (IBS-M)

• Tricyclic antidepressants are the most effective first-line pharmacological treatment for mixed symptoms, starting with amitriptyline 10 mg once daily and titrating to 30-50 mg once daily 1
• Selective serotonin reuptake inhibitors (SSRIs) may be considered if TCAs are not tolerated, though evidence is still under evaluation 2, 1

Probiotics

• Trial probiotics for 12 weeks for global symptoms and bloating; discontinue if no improvement 1
• While specific strains vary in efficacy, probiotics may improve symptoms through modulation of gut microbiota 1

Psychological Therapies (For Refractory Cases)

• Consider IBS-specific cognitive behavioral therapy or gut-directed hypnotherapy when symptoms persist despite pharmacological treatment for 12 months 2, 1
• Initially offer simple relaxation therapy, possibly using audiotapes, before escalating to more intensive interventions 2, 1
• Biofeedback may be especially helpful for disordered defecation 2, 1
• Refer for psychiatric evaluation if serious psychiatric disease is identified (disorders of sleep and mood, history of physical/sexual abuse, poor social support) 2
• Brain-gut behavior therapies are distinct from psychological therapies for depression and anxiety alone; ensure appropriate referral to gastropsychologists when available 2

Treatment Monitoring and Adjustment

• Review treatment efficacy after 3 months and discontinue ineffective medications 1
• Continue TCAs for at least 6 months if patient reports symptomatic improvement 1
• Recognize that symptoms may relapse and remit over time, requiring periodic adjustment of treatment strategy 1

Critical Pitfalls to Avoid

• Do not pursue extensive testing once IBS diagnosis is established in patients under 45 without alarm features (unintentional weight loss ≥5%, blood in stool, fever, anemia, family history of colon cancer or inflammatory bowel disease) 1
• Avoid recommending IgG-based food allergy testing, as true food allergy is rare in IBS 2
• Do not use wheat bran or insoluble fiber, as it frequently worsens symptoms 1
• When prescribing low FODMAP diet, ensure dietitian supervision to prevent nutritional deficits and pathological food-related fear 2
• Be cautious with low FODMAP diet in patients with moderate-to-severe anxiety or depression; consider gentler dietary approaches or Mediterranean diet instead 2
• Titrate loperamide carefully to avoid rebound constipation, abdominal pain, and bloating 1

Multidisciplinary Care Coordination

• Build collaborative links with gastroenterology dietitians and gastropsychologists to coordinate high-quality care 2
• Refer to dietitian if patient reports considerable intake of symptom-triggering foods, requests dietary modification, shows dietary deficits, or demonstrates pathological food-related fear 2
• Refer to gastropsychologist if symptoms or their impact are moderate to severe, patient accepts gut-brain dysregulation concept, and patient has time to devote to learning new coping strategies 2
• Assure patients you will remain involved in their care while working with other practitioners to ensure holistic treatment 2