Care Plan for Irritable Bowel Syndrome (IBS)
IBS management should begin with patient education about the gut-brain axis, followed by a stepwise approach starting with lifestyle modifications and dietary interventions, progressing to pharmacotherapy based on predominant symptoms (diarrhea vs. constipation), and reserving brain-gut behavioral therapies for refractory cases.
Initial Assessment and Diagnosis
Make a positive diagnosis of IBS based on symptoms alone when alarm features are absent, avoiding exhaustive investigation which has low diagnostic yield 1. Perform only limited investigations including celiac serology in all suspected IBS patients 1. Colonoscopy has no role except when alarm symptoms are present or in IBS-D patients with atypical features (nocturnal diarrhea, age ≥50, autoimmune disease, weight loss) to exclude microscopic colitis 1.
Patient Education and Communication
Master patient-friendly language to explain gut-brain axis dysregulation, emphasizing that gastrointestinal and psychological symptoms are real and interconnected 1. Convey empathy and validate that symptoms are taken seriously 1. Adjust visit frequency to accommodate mental health needs, elongating assessments over multiple visits if necessary, especially in patients with trauma history 1.
First-Line Lifestyle and Dietary Management
Exercise
All IBS patients should be advised to take regular exercise as it provides significant symptom management benefits 1, 2.
Dietary Interventions
Start with traditional dietary advice including identification and reduction of excessive lactose, fructose, sorbitol, caffeine, and alcohol 1, 2. Better tolerated foods include water, rice, plain pasta, baked potatoes, white breads, plain fish/chicken/turkey, eggs, and applesauce 3. Foods that commonly worsen symptoms include milk products, caffeine, alcohol, fruits/juices, spices, diet products, fast foods, fried/fatty foods, multigrain breads, salads, beans, red meats, and high fiber 3.
Soluble fiber (ispaghula/psyllium) is effective for global symptoms and abdominal pain, starting at 3-4 g/day and building gradually to avoid bloating 1. Avoid insoluble fiber (wheat bran) as it may exacerbate symptoms 1.
Low FODMAP diet should be considered as second-line dietary therapy for moderate to severe gastrointestinal symptoms, but must be supervised by a trained dietitian with systematic reintroduction according to tolerance 1. For patients with moderate-to-severe anxiety or depression, consider a gentle FODMAP approach or Mediterranean diet instead 1. Do not recommend gluten-free diets as evidence does not support their use 1.
Probiotics
Probiotics may improve global symptoms and abdominal pain, though no specific species or strain can be recommended 1. Advise a 12-week trial and discontinue if no improvement 1, 2.
Symptom-Specific Pharmacotherapy
For IBS with Diarrhea (IBS-D)
First-line: Loperamide 4-12 mg daily is the most effective first-line treatment, significantly reducing stool frequency and urgency 2. Titrate dose carefully to avoid abdominal pain, bloating, nausea, and constipation 1.
Second-line options for IBS-D:
- 5-HT3 receptor antagonists are likely the most efficacious for IBS-D 1. Ondansetron 4 mg once daily titrated to maximum 8 mg three times daily is a reasonable alternative where alosetron/ramosetron are unavailable 1. Constipation is the most common side effect 1.
- Eluxadoline is efficacious but contraindicated in patients with prior sphincter of Oddi problems, cholecystectomy, alcohol dependence, pancreatitis, or severe liver impairment 1.
- Rifaximin is efficacious though its effect on abdominal pain is limited 1.
- Consider bile acid malabsorption testing (SeHCAT scanning or serum 7α-hydroxy-4-cholesten-3-one) in patients with nocturnal diarrhea or prior cholecystectomy; approximately 10% of IBS-D patients respond to cholestyramine 1, 2.
For IBS with Constipation (IBS-C)
First-line: Laxatives should be used initially 1.
Second-line secretagogues when laxatives fail:
- Linaclotide 290 mcg once daily is likely the most efficacious secretagogue for IBS-C 1, 4. Take on empty stomach at least 30 minutes before a meal 4. Diarrhea is a common side effect 1.
- Lubiprostone is less likely to cause diarrhea than other secretagogues 1.
For Abdominal Pain
First-line: Antispasmodics with anticholinergic properties (like dicyclomine) show greater efficacy for pain relief 1, 2. Common side effects include dry mouth, visual disturbance, and dizziness 1.
Second-Line Neuromodulators
Low-dose tricyclic antidepressants (TCAs) are the preferred second-line treatment for global symptoms and abdominal pain in IBS 1. Start amitriptyline at 10 mg once daily and titrate slowly to maximum 30-50 mg once daily 1. Provide careful explanation about their use as gut-brain neuromodulators, not antidepressants, and counsel about side effects 1.
Selective serotonin reuptake inhibitors (SSRIs) should be preferred when concurrent mood disorder is present, as low-dose TCAs are unlikely to address psychological symptoms 1. SSRIs may be effective for global symptoms but have weaker evidence than TCAs 1.
Psychological and Behavioral Interventions
Brain-gut behavioral therapies (BGBTs) should be considered for patients with moderate to severe symptoms refractory to pharmacological treatment for 12 months 2. Cognitive behavioral therapy and gut-directed hypnotherapy have the largest evidence base 1. Mindfulness-based stress reduction is a promising approach that can be delivered in 45-minute daily sessions for 8 weeks 1.
Simple mindfulness strategies can be safely incorporated by non-mental-health professionals, such as dietitians teaching mindful eating exercises 1.
Referral Thresholds
Refer to gastroenterologist if diagnosis is in doubt or symptoms are refractory to primary care treatment 1.
Refer to specialist gastroenterology dietitian if patient consumes diet high in trigger foods, shows dietary deficits or nutritional deficiency, has unintended weight loss, or requests dietary modification advice 1.
Refer to gastropsychologist if patient shows moderate to severe depression/anxiety, suicidal ideation, low social support, impaired quality of life, avoidance behavior, or motivational deficiencies affecting self-management 1.
Refer to psychiatry or specialist psychologist if patient shows severe psychiatric illness, concern about medication misuse, or eating disorder 1.
Treatment Monitoring and Adjustment
Review treatment efficacy after 3 months and discontinue ineffective medications 2. Assure patients you will remain involved in their care and work with other practitioners for holistic treatment 1. Acknowledge that symptoms may relapse and remit over time, requiring periodic treatment adjustment 2.
Common Pitfalls to Avoid
Do not pursue exhaustive investigation once IBS diagnosis is established 1. Do not use IgG antibody-based food elimination diets as they are not recommended 1. Do not implement low FODMAP diet without dietitian supervision or in patients with eating pathology or severe mental illness 1. Do not use low-dose TCAs to treat concurrent mood disorders—use SSRIs instead 1.