What are the management options for a patient with irritable bowel syndrome?

Management of Irritable Bowel Syndrome

Establish Diagnosis and Build Therapeutic Relationship

Make a positive diagnosis using Rome criteria in patients under 45 years without alarm features, avoiding extensive testing that delays treatment and reinforces illness behavior 1, 2, 3. Alarm features requiring investigation include unintentional weight loss, blood in stool, fever, anemia, nocturnal diarrhea, or family history of colon cancer/inflammatory bowel disease 2. Consider limited celiac serology testing in all patients 2.

Provide clear explanation that IBS is a disorder of gut-brain interaction with a benign but relapsing/remitting course 3. Master patient-friendly language about gut-brain axis dysregulation and convey empathy that both gastrointestinal and psychological symptoms are real 4. Adjust visit duration and frequency to accommodate mental health needs, especially if there is history of abuse 4, 3.

Have patients keep a 2-week diary of food intake and gastrointestinal symptoms to identify triggers and engage them in disease management 3, 5.

First-Line Management for All Patients

Lifestyle Modifications

• Prescribe regular physical activity to all IBS patients, as exercise provides significant benefits for symptom management 1, 2, 3
• Establish regular time for defecation and ensure adequate sleep hygiene 1, 2, 3
• Promote patient empowerment through education using handouts, self-help books, websites, and apps targeting physical activity, sleep hygiene, mindful eating, and assertive communication 3

Dietary Interventions Based on Predominant Bowel Pattern

For IBS with Constipation (IBS-C):

• Start soluble fiber supplementation (ispaghula/psyllium) at 3-4 g/day and gradually increase 1, 3
• Avoid insoluble fiber (wheat bran) as it worsens symptoms, particularly bloating 1, 3
• Maintain a balanced diet with appropriate fiber intake 1

For IBS with Diarrhea (IBS-D):

• Decrease fiber intake 3
• Identify and reduce excessive intake of lactose, fructose, sorbitol, caffeine, and alcohol, as these commonly trigger IBS-D symptoms 2

Do not recommend IgG-based food allergy testing, as true food allergy is rare in IBS 1.

Pharmacological Treatment: Symptom-Targeted Approach

For Abdominal Pain

Use antispasmodics with anticholinergic properties (dicyclomine) as first-line therapy for abdominal pain, particularly when symptoms are meal-related 1, 2, 3. For patients with infrequent but severe episodes of unpredictable pain, sublingual hyoscyamine produces rapid relief 5. Peppermint oil may be useful as an alternative antispasmodic 1.

For Diarrhea

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 2, 3. Use in divided doses, with a morning dose before breakfast (2-6 mg) and potentially again later in the day when symptoms are prominent 5. Monitor patients for cardiac adverse reactions, especially when co-administered with CYP3A4 inhibitors, CYP2C8 inhibitors, or P-glycoprotein inhibitors 6.

Consider cholestyramine for patients with prior cholecystectomy or suspected bile acid diarrhea 2.

For Constipation

Soluble fiber as described above is the primary treatment 1. Avoid osmotic laxatives or increasing fiber in IBS-D, as these worsen diarrhea 2.

Second-Line Pharmacological Treatment

Neuromodulators

Use tricyclic antidepressants (amitriptyline/trimipramine) starting at 10 mg once daily and titrating slowly to 30-50 mg once daily for patients with refractory pain, mixed symptoms, or when insomnia is prominent 4, 2, 3. Low-dose tricyclic antidepressants are preferred for gastrointestinal symptoms, particularly pain, and are the most effective first-line neuromodulator with moderate-to-high quality evidence for global symptoms and abdominal pain 4, 2.

A selective serotonin reuptake inhibitor is preferred if there is a concurrent mood disorder 4. Educate patients that side effects occur early and benefits may not be apparent for 3-4 weeks 5.

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, 3. These interventions modify interactions between the gut and brain, addressing how benign sensations induce maladaptive cognitive or affective processes that amplify symptom perception 7.

Offer explanation, reassurance, and simple relaxation therapy using audiotapes 2. Biofeedback may be especially helpful for disordered defecation 1.

Multidisciplinary Referral Criteria

Refer to gastroenterology dietitian if:

• Patient consumes considerable intake of foods that trigger IBS symptoms 1, 2, 3
• Shows dietary deficits or nutritional deficiency 1, 2, 3
• Shows recent unintended weight loss 3
• Requests or is receptive to dietary modification advice 3

Low FODMAP diet should be reserved for patients with access to a specialist dietitian 4.

Refer to gastropsychologist if:

• IBS symptoms or their impact are moderate to severe 4, 3
• Patient shows moderate to severe symptoms of depression or anxiety, suicidal ideation and hopelessness 4
• Has a low social support system, impaired quality of life or avoidance behavior 4
• Shows motivational deficiencies that affect ability to self-manage or adhere to treatment recommendations 4
• Patient accepts that symptoms are related to gut-brain dysregulation and has time to devote to learning new coping strategies 1, 3

Refer to gastroenterology if:

• The diagnosis of IBS is in doubt and symptoms have proven refractory to treatment in primary care 4, 2

Refer to psychiatry or specialist psychologist if:

• Patient shows severe psychiatric illness and/or psychiatric medication use 4
• There is concern about the use or misuse of anxiety medication or opiates 4
• Patient has an eating disorder 4

Addressing Mental Health Comorbidity

Screen for psychological disorders even if you are not a mental health provider, as gastroenterologists and dietitians may be the first to observe emotional difficulties 4, 3. Assess whether diagnosed co-occurring psychological disorders (anxiety or depression) are adequately treated, as under-managed anxiety and depression negatively affect responses to IBS treatment 4, 3.

When assessing responses to psychological treatment of IBS, progress must be measured in both physical and psychological domains 4. Inform the patient's referring doctor, general practitioner or mental health provider about any changes in the patient's wellbeing, particularly if there is risk of self-harm or harm to others 4.

Treatment Monitoring and Follow-Up

Review treatment efficacy after 3 months and discontinue ineffective medications 1, 2, 3. Recognize that symptoms may relapse and remit over time, requiring periodic adjustment of treatment strategy 3.

Critical Pitfalls to Avoid

• Do not pursue extensive testing once IBS diagnosis is established in patients under 45 without alarm features 1, 2, 3
• Avoid insoluble fiber (wheat bran) as it worsens symptoms 1, 3
• Do not recommend IgG-based food allergy testing 1
• Avoid reinforcing abnormal illness behavior through repeated unnecessary consultations and procedures 3
• Do not use osmotic laxatives or increase fiber in IBS-D, as these worsen diarrhea 2
• Avoid loperamide in elderly patients taking drugs that can result in prolongation of the QT interval (Class IA or III antiarrhythmics) or in patients with risk factors for Torsades de Pointes 6