Treatment Options for Irritable Bowel Syndrome with Diarrhea (IBS-D)

Loperamide at doses of 4-12 mg daily is the most effective first-line treatment for IBS-D, significantly reducing stool frequency and urgency. 1

First-Line Treatments

Identify and reduce excessive intake of lactose, fructose, sorbitol, caffeine, or alcohol in patients with diarrhea 2, 1
Consider decreasing fiber intake for patients with diarrhea, as excessive fiber may worsen symptoms 2
Regular exercise provides significant benefits for symptom management 1
A trial of low FODMAP diet under supervision of a trained dietitian may be considered for patients with persistent symptoms 1
Soluble fiber (ispaghula/psyllium) may be beneficial, starting with low doses (3-4g/day) and gradually increasing to avoid bloating 1

Loperamide (4-12 mg daily) effectively slows intestinal transit and reduces stool frequency and urgency, can be used regularly or prophylactically (e.g., before going out) 2, 1
Codeine (30-60 mg, 1-3 times daily) is effective for diarrhea but may cause sedation and dependency 2, 1
Cholestyramine may specifically benefit a small number of patients with bile salt malabsorption but is often less well tolerated than loperamide 2, 1

Rifaximin (550 mg three times daily for 14 days) is FDA-approved for IBS-D in adults, with the possibility of retreatment up to two times for symptom recurrence 3, 4
Eluxadoline is indicated for the treatment of IBS-D in adults 5, 4
Alosetron is approved only for women with severe IBS-D refractory to other treatments 4

Antispasmodics with anticholinergic properties (like dicyclomine) show efficacy for pain relief 2, 1
Tricyclic antidepressants (TCAs) such as amitriptyline/trimipramine are effective for pain and global symptoms in IBS-D, especially when insomnia is prominent, but may aggravate constipation 2, 1
Selective serotonin reuptake inhibitors (SSRIs) may be considered if TCAs are not tolerated 1

Initially provide explanation and reassurance about the brain-gut interaction 2, 1
Trial of simple relaxation therapy, possibly using audiotapes 2
Consider IBS-specific cognitive behavioral therapy or gut-directed hypnotherapy for patients with symptoms refractory to pharmacological treatment 1
Biofeedback may be especially helpful for disordered defecation 2

Start with loperamide 4-12 mg daily as first-line therapy for diarrhea control 1
Implement dietary modifications by identifying and reducing problematic foods (lactose, fructose, sorbitol, caffeine, alcohol) 2, 1
For persistent symptoms:
- Add antispasmodics for pain relief 2, 1
- Consider trial of low FODMAP diet under dietitian supervision 1
- Evaluate for bile salt malabsorption and consider cholestyramine if suspected 1
For refractory symptoms:
- Consider FDA-approved medications: rifaximin, eluxadoline, or alosetron (women only) 3, 5, 4
- Trial tricyclic antidepressants for pain and global symptoms 2, 1
- Implement psychological therapies such as cognitive behavioral therapy or gut-directed hypnotherapy 1

Review treatment efficacy after 3 months and discontinue ineffective medications 1
Recognize that IBS is a disorder of gut-brain interaction requiring explanation of the gut-brain axis to patients 1
Acknowledge that symptoms may relapse and remit over time, requiring periodic adjustment of treatment strategy 1
Rifaximin has the most favorable safety profile among the FDA-approved agents for IBS-D 6
Avoid extensive testing once IBS-D diagnosis is established 1
When using codeine, be aware that CNS effects are often unacceptable to patients 2