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

Treatment Options for Irritable Bowel Syndrome (IBS)

The treatment of IBS should follow a step-wise approach starting with lifestyle modifications, dietary changes, and first-line medications targeted to predominant symptoms, progressing to psychological therapies and second-line pharmacological options for refractory cases. 1

First-Line Management

Patient Education and Reassurance

• Provide a clear explanation of IBS as a disorder of gut-brain interaction with a benign but relapsing/remitting course 1
• Address patient concerns and identify beliefs; a symptom diary may be helpful 1
• Explain the brain-gut interaction and how stress may aggravate symptoms 1

Lifestyle Modifications

• Recommend regular exercise, which has shown benefits particularly for constipation with effects lasting up to 5 years 1
• Establish healthy routines including regular time for defecation 1
• Consider relaxation therapy for patients with anxiety but without psychiatric disease 1

Dietary Interventions

• Establish habitual fiber intake and provide simple explanation of how fiber affects bowel function 1
• For constipation-predominant IBS (IBS-C): increase dietary fiber or try ispaghula/psyllium 1
• For diarrhea-predominant IBS (IBS-D): decrease fiber intake and identify excessive consumption of lactose, fructose, sorbitol, caffeine, or alcohol 1, 2
• Consider a low FODMAP diet as a second-line dietary therapy under supervision of a dietitian 1, 2
• Trial of lactose/fructose/alcohol exclusion if appropriate 1

Probiotics

• Consider a trial of probiotics for overall symptom improvement 3, 2

Pharmacological Approach Based on Predominant Symptoms

For Abdominal Pain

• Antispasmodics: anticholinergic agents like dicyclomine 1
• Peppermint oil has sufficient evidence for symptom reduction 2

For Diarrhea-Predominant IBS

• Loperamide 4-12 mg daily (regularly or prophylactically) 1
• Codeine 30-60 mg 1-3 times daily can be tried but CNS effects often limit use 1
• Cholestyramine may benefit a small number of patients but is often less tolerated than loperamide 1

For Constipation-Predominant IBS

• Increase dietary fiber or use ispaghula/psyllium if symptoms are exacerbated by bran 1
• Consider linaclotide, which has shown efficacy in clinical trials for IBS-C 4

For Bloating

• Try reducing intake of fiber/lactose/fructose as relevant 1

Second-Line Treatments

Gut-Brain Neuromodulators

• Tricyclic antidepressants (TCAs) like amitriptyline/trimipramine, especially when insomnia is prominent (may aggravate constipation) 1
• Start at low dose (10 mg at night) and titrate slowly according to response and tolerability 1
• Continue for at least 6 months if symptomatic response is reported 1
• Selective serotonin reuptake inhibitors (SSRIs) may be considered but evidence is still under evaluation 1

Psychological Therapies

• Consider for patients with refractory symptoms or prominent psychological factors 1
• Options include:
  • Cognitive behavioral therapy (CBT) 1
  • Gut-directed hypnotherapy 1
  • Biofeedback, especially for disordered defecation 1
  • Dynamic psychotherapy for those with significant psychological morbidity 1

Treatment Algorithm

1. Start with lifestyle modifications, dietary advice, and probiotics 1
2. Add symptom-specific medications based on predominant symptoms 1
3. Review efficacy after 3 months and discontinue if no response 1
4. For persistent symptoms, consider gut-brain neuromodulators (TCAs first choice) 1
5. Refer for psychological therapies (CBT or gut-directed hypnotherapy) if available and patient is amenable 1
6. Consider psychological therapies earlier based on patient preference or when symptoms are refractory to drug treatment for 12 months 1

Common Pitfalls to Avoid

• Overinvestigation can reinforce illness behavior 1
• Focusing solely on symptom management without addressing psychological factors 5
• Expecting complete resolution rather than symptom improvement 3
• Using insoluble fiber (like wheat bran) in patients who may experience worsening symptoms 1