What are the management options for irritable bowel syndrome (IBS)?

Management of Irritable Bowel Syndrome

Start all IBS patients with lifestyle modifications and dietary counseling, escalate to pharmacological therapy based on predominant symptoms (antispasmodics for pain, loperamide for diarrhea, fiber/laxatives for constipation), and reserve neuromodulators and psychological therapies for refractory cases. 1, 2

Initial Approach and Patient Education

Provide a clear explanation that IBS is a disorder of gut-brain interaction with a benign but relapsing/remitting course to establish realistic expectations. 1 Listen to patient concerns, identify their beliefs about the condition, and address fears directly rather than ordering extensive testing once diagnosis is established. 1

Diagnostic Testing to Consider

• Obtain serological testing to exclude celiac disease. 3
• Do not routinely test for C-reactive protein, fecal calprotectin, or IgG-based food allergy testing. 1, 3
• Avoid extensive testing 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, 2

First-Line Management: Lifestyle and Dietary Modifications

Lifestyle Changes

Recommend regular physical activity to all patients with IBS, as exercise provides significant benefits for symptom management. 1, 2 Advise balanced diet with adequate fiber intake, regular time for defecation, and proper sleep hygiene. 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). 1, 2 Avoid insoluble fiber (wheat bran) as it may worsen symptoms, particularly bloating. 1, 3

For patients with moderate to severe gastrointestinal symptoms, refer to a trained dietitian for a supervised trial of low FODMAP diet delivered in three phases: restriction, reintroduction, and personalization. 1, 2 This approach is particularly effective but requires professional guidance to avoid nutritional deficits. 4, 5

Important caveat: For patients with co-occurring moderate-to-severe anxiety or depression, a gentle FODMAP diet or Mediterranean diet should be considered instead of strict FODMAP restriction. 4 Do not recommend a gluten-free diet unless celiac disease is confirmed. 3

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. 1, 2 Peppermint oil may be used as an alternative antispasmodic, though evidence is more limited. 1, 2, 3

For Diarrhea-Predominant IBS (IBS-D)

Prescribe loperamide 4-12 mg daily (either regularly or prophylactically before going out) as first-line therapy to reduce stool frequency, urgency, and fecal soiling. 1, 2 This effectively slows intestinal transit and is well-tolerated. 2

For refractory IBS-D, eluxadoline is FDA-approved for treatment of IBS-D in adults. 6

Common pitfall: Codeine 30-60 mg, 1-3 times daily can be tried but central nervous system effects often limit use. 2 Cholestyramine may benefit a small subset of patients with bile salt malabsorption but is often less well tolerated than loperamide. 2

For Constipation-Predominant IBS (IBS-C)

Increase dietary fiber or use soluble fiber supplements like ispaghula/psyllium as first-line treatment. 2 For patients who fail to respond to fiber and laxatives, prescribe linaclotide. 7

Lubiprostone 8 mcg twice daily is FDA-approved for treatment of IBS-C in women at least 18 years old, taken orally with food and water. 8

For Bloating

Trial probiotics for 12 weeks for global symptoms and bloating; discontinue if no improvement. 1, 2 Consider reducing intake of fiber, lactose, or fructose as relevant. 2

Second-Line Treatment: Neuromodulators

For patients with mixed symptoms or refractory pain, prescribe tricyclic antidepressants (TCAs) starting with amitriptyline 10 mg once daily and titrating to 30-50 mg once daily. 4, 1, 2 Low-dose TCAs are preferred for gastrointestinal symptoms, particularly pain, and are the most effective first-line pharmacological treatment for mixed IBS. 4, 1

Critical distinction: If there is a concurrent mood disorder, use a selective serotonin reuptake inhibitor (SSRI) instead, because low-dose TCAs are unlikely to address psychological symptoms. 4, 2

Continue TCAs for at least 6 months if the patient reports symptomatic improvement. 2 Review treatment efficacy after 3 months and discontinue ineffective medications. 2

Important caveat: TCAs may aggravate constipation, so use with caution in IBS-C. 2

Psychological Therapies for Refractory Cases

Consider IBS-specific cognitive behavioral therapy or gut-directed hypnotherapy when symptoms persist despite pharmacological treatment for 12 months. 1, 2 These brain-gut behavior therapies are specifically designed for IBS and differ from psychological therapies that target depression and anxiety alone. 4

Initially offer explanation, reassurance, and simple relaxation therapy. 2 Biofeedback may be especially helpful for disordered defecation. 2

Multidisciplinary Care Coordination

Build collaborative links with gastroenterology dietitians and gastropsychologists to coordinate high-quality care. 1, 2

Thresholds for Referral to Dietitian

Refer if the patient reports considerable intake of foods that trigger IBS symptoms, requests dietary modification advice, has dietary deficits or nutrition red flags (avoidance of multiple food groups, unintentional weight loss ≥5% in previous 6 months, nutrient deficiency), or has pathological food-related fear. 4

Thresholds for Referral to Gastropsychologist

Refer if IBS symptoms or their impact are moderate to severe, the patient accepts that symptoms are related to gut-brain dysregulation, and the patient has time to devote to learning new coping strategies. 4

Enhancing Patient Self-Management

Promote patient empowerment through education and psychoeducation using handouts, self-help books, websites, and apps. 4 Target physical activity, sleep hygiene, mindful eating, and assertive communication. 4 Self-management techniques improve IBS symptoms and quality of life in the short term. 4

Assure patients that you will remain involved in their care and work with their other practitioners to ensure they are treated holistically. 4 Recognize that symptoms may relapse and remit over time, requiring periodic adjustment of treatment strategy. 2