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

Management of Irritable Bowel Syndrome (IBS)

A comprehensive approach to IBS management should include dietary modifications, lifestyle changes, psychological interventions, and targeted pharmacological treatments based on predominant symptoms. 1

Diagnosis and Initial Approach

• Make a positive diagnosis in patients <45 years meeting Rome criteria without alarm features
• Address patient concerns and identify beliefs; symptom diaries can be helpful
• Provide explanation and reassurance about the benign but relapsing nature of IBS
• Discuss brain-gut interaction and how stress may aggravate symptoms

Dietary Management

First-Line Dietary Approach

• Establish habitual fiber intake and adjust accordingly:
  • Increase fiber for constipation-predominant IBS (IBS-C)
  • Decrease fiber for diarrhea-predominant IBS (IBS-D)
• Recommend balanced diet with regular meal patterns
• Identify and limit intake of trigger foods:
  • Lactose, fructose, sorbitol, caffeine, and alcohol in IBS-D patients
  • Trial exclusion of these substances if appropriate

Second-Line Dietary Approach

• Consider low FODMAP diet for persistent symptoms, implemented under dietitian supervision 2, 3
• Better tolerated foods include:
  • Water, rice, plain pasta, white breads, plain fish, chicken, turkey, eggs
  • Baked potatoes, dry cereals, applesauce, cantaloupe, watermelon 4

Pharmacological Management

For Abdominal Pain

1. First-line: Antispasmodics (anticholinergic agents like dicyclomine) 1
2. Second-line: Tricyclic antidepressants (amitriptyline/trimipramine 10-50mg at bedtime) 1, 5
   • Particularly helpful when insomnia is prominent
   • May aggravate constipation
3. Alternative: Selective serotonin reuptake inhibitors (still under evaluation) 1

For Diarrhea (IBS-D)

1. First-line: Loperamide 4-12 mg daily (regularly or prophylactically) 1
2. Second-line:
   • Codeine 30-60 mg, 1-3 times daily (CNS effects often unacceptable) 1
   • Cholestyramine (may benefit some patients but often less tolerated than loperamide) 1

For Constipation (IBS-C)

1. First-line: Increase dietary fiber or try ispaghula/psyllium if symptoms worsen with bran 1
2. Second-line: Osmotic laxatives (polyethylene glycol) 5
3. Third-line: Secretagogues like linaclotide (FDA-approved for IBS-C in adults) 6, 5
   • Shown to improve abdominal pain and increase complete spontaneous bowel movements

For Bloating

• Try reducing intake of fiber/lactose/fructose as relevant 1
• Consider rifaximin for bacterial overgrowth in selected cases 7

Psychological Interventions

When to Consider

• For patients with psychological factors contributing to symptoms
• For those with refractory symptoms despite dietary and pharmacological management

Options

1. First-line: Explanation, reassurance, and simple relaxation techniques 1
2. Second-line (limited availability):
   • Biofeedback (especially for disordered defecation)
   • Hypnotherapy (exclude those with overt psychiatric disease)
   • Cognitive behavioral therapy
   • Dynamic psychotherapy 1
3. Severe cases: Psychiatric referral for serious psychiatric disease 1

Step-wise Treatment Algorithm

1. Start with dietary modifications and lifestyle changes
2. Add targeted pharmacotherapy based on predominant symptom:
   • Pain → antispasmodics → tricyclic antidepressants
   • Diarrhea → loperamide → cholestyramine/codeine
   • Constipation → fiber → osmotic laxatives → secretagogues
   • Bloating → dietary modifications → consider antibiotics
3. For persistent symptoms, add psychological interventions
4. Review efficacy after 3 months and adjust treatment accordingly

Common Pitfalls and Caveats

• Avoid extensive testing in patients <45 years meeting diagnostic criteria without alarm features
• Don't overlook psychological factors that may exacerbate symptoms
• Avoid opioid analgesics for chronic abdominal pain as they can worsen gastrointestinal dysmotility
• Be aware that tricyclic antidepressants may aggravate constipation
• Recognize that true food allergies are rare, but food intolerances are common
• Remember that treatment response is often partial rather than complete resolution of symptoms

By following this structured approach to IBS management, clinicians can effectively address symptoms and improve patients' quality of life while minimizing unnecessary testing and treatments.